Document:

EX-4.1

 Exhibit 4.1 

ENGAGESMART, INC. 

REGISTRATION RIGHTS AGREEMENT 

This REGISTRATION RIGHTS AGREEMENT (this “Agreement”) is made as of _______, 2021, by and among EngageSmart, Inc., a Delaware
corporation (the “Company”), General Atlantic (IC), L.P., a Delaware limited partnership (together with its affiliated investment entities, “General Atlantic”), Summit Partners Growth Equity Fund VIII-A, L.P., a Delaware limited partnership, Summit Partners Growth Equity Fund VIII-B, L.P., a Delaware limited partnership, Summit Partners Entrepreneur Advisors Fund I,
L.P., a Delaware limited partnership, Summit Investors I, LLC, a Delaware limited liability company and Summit Investors I (UK), L.P., a Cayman Islands exempted limited partnership (collectively, “Summit”), and each of the investors
listed on the signature pages hereto under the caption “Investors” (collectively, the “Investors” and individually, an “Investor”), and each other Person listed on the signature pages hereto under the
caption “Other Holders” or who executes a Joinder as an “Other Holder” (collectively, the “Other Holders”). Except as otherwise specified herein, all capitalized terms used in this Agreement are
defined in Exhibit A attached hereto. 
 In consideration of the mutual covenants contained herein and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the parties to this Agreement hereby agree as follows: 

Section 1 Demand Registrations. 

(a) Requests for Registration. At any time and from time to time, the Investors or an Investor may, in each case, request registration
under the Securities Act of all or any portion of their Registrable Securities on Form S-1 or any similar long-form registration statement (“Long-Form Registrations”) or on Form S-3 or any similar short-form registration statement (“Short-Form Registrations”) if available (any such requested registration, a “Demand Registration”). The Investor
making the demand may request that any Demand Registration be made pursuant to Rule 415 under the Securities Act (a “Shelf Registration”) and (if the Company is a WKSI at the time any such request is submitted to the Company or will
become one by the time of the filing of such Shelf Registration with the SEC) that such Shelf Registration be an automatic shelf registration statement (as defined in Rule 405 under the Securities Act) (an “Automatic Shelf Registration
Statement”). Each request for a Demand Registration must specify the approximate number or dollar value of Registrable Securities requested to be registered by the requesting Holders and (if known) the intended method of distribution.
Subject to Section 1(e), (i) General Atlantic will be entitled to request an unlimited number of Demand Registrations and Summit will be entitled to request one (1) Long-Form Registration and one (1) Short-Form
Registration, in which the Company will pay all Registration Expenses, whether or not any such registration is consummated, provided that the aggregate anticipated offering price, net of any underwriting discounts or commissions, of each such
offering is at least $100,000,000 and (ii) any Demand Registration may, at the Company’s option, include securities to be sold by the Company for its own account. 

 (b) Notice to Other Holders. Within ten (10) days after receipt of any such
request, the Company will give written notice of the Demand Registration to all other Holders and, subject to the terms of Section 1(e), will include in such Demand Registration (and in all related registrations and
qualifications under state blue sky laws and in any related underwriting agreement) all Registrable Securities with respect to which the Company has received written requests for inclusion therein within ten (10) days after the receipt of the
Company’s notice; provided that, with the consent of the Majority Participating Investors, which consent shall not be unreasonably withheld, conditioned or delayed, the Company may instead provide notice of the Demand Registration to all
Other Holders within three (3) Business Days following the non-confidential filing of the registration statement with respect to the Demand Registration so long as such registration statement is not an
Automatic Shelf Registration Statement. 
 (c) Form of Registrations. All Long-Form
Registrations will be underwritten registrations unless otherwise approved by the Majority Participating Investors. Demand Registrations will be Short-Form Registrations whenever the Company is permitted to use any applicable short form.  
 (d) Shelf Registrations. 

(i) For so long as a registration statement for a Shelf Registration (a “Shelf Registration Statement”) is and
remains effective, any Investor will have the right at any time or from time to time to elect to sell pursuant to an offering (including an underwritten offering, provided that the aggregate anticipated offering price, net of any underwriting
discounts and commissions, of each such underwritten offering is at least $25,000,000, subject to Section 1(d)(v)) Registrable Securities available for sale pursuant to such registration statement (such Registrable Securities, the
“Shelf Registrable Securities”), which may include Shelf Registrable Securities to be sold by the Investor. If any Investor desires to sell Registrable Securities pursuant to an underwritten offering, such Investor shall deliver to
the Company a written notice (a “Shelf Offering Notice”) specifying the number of Shelf Registrable Securities that such Investor desires to sell pursuant to such underwritten offering (the “Shelf Offering”). As
promptly as practicable, but in no event later than two (2) Business Days after receipt of a Shelf Offering Notice, the Company will give written notice of such Shelf Offering Notice to all other Holders of Shelf Registrable Securities that
have been identified as selling stockholders in such Shelf Registration Statement and are otherwise permitted to sell in such Shelf Offering. The Company, subject to Section 1(e) and Section 7,
will include in such Shelf Offering all Shelf Registrable Securities with respect to which the Company has received written requests for inclusion (which request will specify the maximum number of Shelf Registrable Securities intended to be disposed
of by such Holder) within seven (7) days after the receipt of the Shelf Offering Notice. The Company will, as soon as reasonably practicable (and in any event within 20 days after the receipt of a Shelf Offering Notice), but subject to
Section 1(e), use its reasonable best efforts to facilitate such Shelf Offering. 
 (ii) If any
Investor wishes to engage in an underwritten block trade or bought deal off of a Shelf Registration Statement (either through filing an Automatic Shelf Registration Statement or through a take-down from an already existing Shelf Registration
Statement) (each, an “Underwritten Block Trade”), then notwithstanding the time periods set forth in Section 1(d)(i), such Investor will notify the Company of the Underwritten Block Trade not less than two
(2) Business Days prior to the day such offering is first anticipated to commence. The Company will promptly notify each other Holder of 

  
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Investor Registrable Securities and, only if requested by the Majority Participating Investors, each Other Holder, of such Underwritten Block Trade and such notified Holders (each, a
“Potential Participant”) may elect whether or not to participate no later than the next Business Day (i.e. one (1) Business Day prior to the day such offering is to commence), if the initiating Investor initially
provides two (2) Business Days’ notice to the Company) (unless a longer period is agreed to by the Majority Participating Investors), and the Company will as expeditiously as possible use its reasonable best efforts to facilitate such
Underwritten Block Trade (which may close as early as two (2) Business Days after the date it commences); provided further that, notwithstanding the provisions of Section 1(d)(i), no Holder (other than
Holders of Investor Registrable Securities) will be permitted to participate in an Underwritten Block Trade without the written consent of the Majority Participating Investors. Any Potential Participant’s request to participate in an
Underwritten Block Trade shall be binding on the Potential Participant; provided, that each such Potential Participant that elects to participate may condition its participation on the Underwritten Block Trade being completed within fifteen
(15) Business Days of its acceptance at a price per share (after giving effect to any underwriters’ discounts or commissions) to such Potential Participant of not less than ninety percent (90%) of the closing price for the shares on their
principal trading market on the Business Day immediately prior to such Potential Participant’s election to participate (the “Participation Conditions”). 

(iii) Subject to the Participation Conditions (to the extent applicable), all determinations as to whether to complete any
Shelf Offering and as to the timing, manner, price and other terms of any Shelf Offering contemplated by this Section 1(d) shall be determined by the Majority Participating Investors, and the Company shall use its
reasonable best efforts to cause any Shelf Offering to occur as promptly as practicable. 
 (iv) The Company will, at the
request of the Majority Participating Investors, file any prospectus supplement or any post-effective amendments and otherwise take any action necessary to include therein all disclosure and language deemed necessary or advisable by the Majority
Participating Investors to effect such Shelf Offering. 
 (v) Subject to Section 1(e), General
Atlantic will be entitled to submit an unlimited number of Shelf Offering Notices and Summit will be entitled to submit two (2) Shelf Offering Notices, provided that the aggregate anticipated offering price, net of any underwriting
discounts and commissions, of each such offering is at least $25,000,000. 
 (e) Priority on Demand Registrations and Shelf
Offerings. The Company will not include in any Demand Registration any securities which are not Registrable Securities or securities to be sold for the Company’s own account without the prior written consent of the Majority Participating
Investors. If a Demand Registration or a Shelf Offering is an underwritten offering and the managing underwriters advise the Company in writing that in their reasonable and good faith opinion the number of Registrable Securities and (if permitted
hereunder) other securities requested to be included in such offering exceeds the number of Registrable Securities and other securities (if any), which can be sold therein without adversely affecting the marketability, proposed offering price,
timing or method of distribution of the offering, then the Company will include in such offering (prior to the inclusion of any securities which are not 

  
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Registrable Securities): (i) first, the number of Investor Registrable Securities requested to be included which, in the reasonable and good faith opinion of such underwriters, can be
sold, without any such adverse effect, pro rata among the Participating Investors on the basis of the number of Investor Registrable Securities owned by each such Participating Investor; (ii) second, the number of Registrable Securities
requested to be included by Other Holders which, in the reasonable and good faith opinion of such underwriters, can be sold, without any such adverse effect, pro rata among the respective Other Holders on the basis of the number of Registrable
Securities owned by each such Other Holder and (iii) third, the number of shares of Common Equity proposed to be included by the Company. 

(f) Restrictions on Demand Registration and Shelf Offerings. 

(i) The Company may postpone, for up to 90 days from the date of the request (the “Suspension Period”), the
filing or the effectiveness of a registration statement for a Demand Registration or suspend the use of a prospectus that is part of a Shelf Registration Statement (and therefore suspend sales of the Shelf Registrable Securities) by providing
written notice to the Holders, to be in the form of a certificate signed by the Company’s chief executive officer or chief financial officer stating that matters contained in such certificate reflect the good faith judgment of the board of
directors of the Company, if the following conditions are met: (A) the Company determines that the offer or sale of Registrable Securities would reasonably be expected to have a material adverse effect on any proposal or plan by the Company or
any Subsidiary to engage in any material acquisition of assets or stock (other than in the ordinary course of business) or any material merger, consolidation, tender offer, recapitalization, reorganization, financing or other transaction involving
the Company and (B) upon advice of counsel, the sale of Registrable Securities pursuant to the registration statement would require disclosure of material non-public information not otherwise required to be disclosed under applicable law, and
either (x) the Company has a bona fide business purpose for preserving the confidentiality of such transaction, (y) disclosure would have a material adverse effect on the Company or the Company’s ability to consummate such
transaction, or (z) such transaction renders the Company unable to comply with SEC requirements, in each case under circumstances that would make it impractical or inadvisable to cause the registration statement (or such filings) to become
effective or to promptly amend or supplement the registration statement on a post effective basis, as applicable. The Company may delay or suspend the effectiveness of a Demand Registration or Shelf Registration Statement pursuant to this
Section 1(f)(i) only once in any twelve (12)-month period (for avoidance of doubt, in addition to the Company’s rights and obligations under Section 4(a)(vi)); provided that the Company
shall not register any securities for its own account or that of any other stockholder during such 90 day period other than pursuant to a registration relating to the sale of securities to employees of the Company or a subsidiary pursuant to a stock
option, stock purchase, or similar plan. 
 (ii) In the case of an event that causes the Company to suspend the use of a
Shelf Registration Statement as set forth in paragraph (f)(i) above or pursuant to Section 4(a)(vi) (a “Suspension Event”), the Company will give a notice to the Holders
whose Registrable Securities are registered pursuant to such Shelf Registration Statement (a “Suspension Notice”) to suspend sales of the Registrable Securities and such notice must 

  
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state generally the basis for the notice and that such suspension will continue only for so long as the Suspension Event or its effect is continuing. Each Holder agrees not to effect any sales of
its Registrable Securities pursuant to such Shelf Registration Statement (or such filings) at any time after it has received a Suspension Notice from the Company and prior to receipt of an End of Suspension Notice. A Holder may recommence effecting
sales of the Registrable Securities pursuant to the Shelf Registration Statement (or such filings) following further written notice to such effect (an “End of Suspension Notice”) from the Company, which End of Suspension Notice will
be given by the Company to the Holders promptly following the conclusion of any Suspension Event (and in any event during the permitted Suspension Period). 

(g) Selection of Underwriters. The Majority Participating Investors will have the right to select the investment banker(s) and
manager(s) to administer any underwritten offering in connection with any Demand Registration or Shelf Offering, provided that if any such offering includes securities to be sold by the Company for its own account, such selection shall be
reasonably acceptable to the Company. 
 (h) Other Registration Rights. Except as provided in this Agreement, the Company will not
grant to any Person(s) the right to request the Company or any Subsidiary to register any equity securities of the Company or any Subsidiary, or any securities convertible or exchangeable into or exercisable for such securities, without the prior
written consent of the Majority Investors. 
 (i) Revocation of Demand Notice or Shelf Offering Notice. At any time prior to the
effective date of the registration statement relating to a Demand Registration or the “pricing” of any offering relating to a Shelf Offering Notice, the Investors who initiated such Demand Registration or Shelf Offering may revoke such
notice of a Demand Registration or Shelf Offering Notice on behalf of all Holders participating in such Demand Registration or Shelf Offering without liability to such Holders (including, for the avoidance of doubt, the other Participating
Investors), in each case by providing written notice to the Company, provided, however, that any other Participating Investor that would otherwise have the right to request such Demand Registration or Shelf Offering in the first instance may in such
case request the Company to continue with such Demand Registration or Shelf Offering with such other Investor taking the place of the Investor that originally made such Demand Registration or requested such Shelf Offering. 

(j) Confidentiality. Each Holder agrees to treat as confidential the receipt of any notice hereunder (including notice of a Demand
Registration, a Shelf Offering Notice and a Suspension Notice) and the information contained therein, and not to disclose or use the information contained in any such notice (or the existence thereof) without the prior written consent of the Company
until such time as the information contained therein is or becomes available to the public generally (other than as a result of disclosure by such Holder in breach of the terms of this Agreement). 

  
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 Section 2 Piggyback Registrations. 

(a) Right to Piggyback. Whenever the Company proposes to register any of its equity securities under the Securities Act (including
primary and secondary registrations, and other than pursuant to an Excluded Registration) (a “Piggyback Registration”), the Company will give prompt written notice (and in any event within three (3) Business Days after
the public filing of the registration statement relating to the Piggyback Registration) to all Holders of its intention to effect such Piggyback Registration and, subject to the terms of Section 2(b) and
Section 2(c), will include in such Piggyback Registration (and in all related registrations or qualifications under blue sky laws and in any related underwriting) all Registrable Securities with respect to which the Company
has received written requests for inclusion therein within ten (10) days after delivery of the Company’s notice. Any Participating Investor may withdraw its request for inclusion at any time prior to executing the underwriting agreement,
or if none, prior to the applicable registration statement becoming effective. For certainty, any Participating Investor who has withdrawn its request for inclusion shall nevertheless continue to have the right to include any Registrable Securities
in any subsequent registration statement or registration statements as may be filed by the Company with respect to offerings of its securities, all upon the terms and conditions set forth herein. 

(b) Priority on Primary Registrations. If a Piggyback Registration is an underwritten primary registration on behalf of the Company,
and the managing underwriters advise the Company in writing that in their reasonable and good faith opinion the number of securities requested to be included in such registration exceeds the number which can be sold in such offering without
adversely affecting the marketability, proposed offering price, timing or method of distribution of the offering, the Company will include in such registration (i) first, the securities the Company proposes to sell, (ii) second, the
Registrable Securities requested to be included in such registration which, in the reasonable and good faith opinion of the underwriters, can be sold without any such adverse effect, pro rata among the Holders on the basis of the number of
Registrable Securities owned by each such Holder, and (iii) third, other securities requested to be included in such registration which, in the reasonable and good faith opinion of the underwriters, can be sold without any such adverse
effect. 
 (c) Priority on Secondary Registrations. If a Piggyback Registration is an underwritten secondary registration on behalf
of holders of the Company’s equity securities (other than pursuant to Section 1 hereof), and the managing underwriters advise the Company in writing that in their reasonable and good faith opinion the number of
securities requested to be included in such registration exceeds the number which can be sold in such offering without adversely affecting the marketability, proposed offering price, timing or method of distribution of the offering, the Company will
include in such registration (i) first, the securities requested to be included therein by the holders initially requesting such registration and the Investor Registrable Securities requested to be included in such registration which, in
the reasonable and good faith opinion of the underwriters, can be sold without any such adverse effect, (ii) second, the Registrable Securities requested to be included in such registration, pro rata among the other Holders on the basis
of the number of Registrable Securities owned by each such Holder, which, in the reasonable and good faith opinion of the underwriters, can be sold without any such adverse effect, and (iii) third, other securities requested to be
included in such registration which, in the reasonable and good faith opinion of the underwriters, can be sold without any such adverse effect. 

  
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 (d) Right to Terminate Registration. The Company will have the right to terminate or
withdraw any registration initiated by it under this Section 2, whether or not any holder of Registrable Securities has elected to include securities in such registration. 

(e) Selection of Underwriters. If any Piggyback Registration is an underwritten offering under which the majority of the Common Equity
proposed to be sold would be sold by the Company for its own account, then the Company will be entitled to select the investment banker(s) and manager(s) for such offering. If any Piggyback Registration is an underwritten offering under which less
than a majority of the Common Equity proposed to be sold would be sold by the Company for its own account, then the selection of investment banker(s) and manager(s) for the offering must be approved by the Majority Participating Investors, which
approval shall not be unreasonably withheld, conditioned, or delayed. 
 Section 3 Stockholder
Lock-Up Agreements and Company Holdback Agreement. 
 (a) Stockholder Lock-up Agreements. In connection with any underwritten Public Offering, each Holder will enter into any lock-up, holdback or similar agreements requested by the
underwriter(s) managing such offering, in each case with such modifications and exceptions as may be reasonably approved by the Majority Participating Investors (provided that such lock-up, holdback or similar
agreements shall be on the same terms and conditions as any such agreement executed by the Majority Participating Investors unless otherwise agreed in writing by such other Holder or Holders). Without limiting the generality of the foregoing, each
Holder hereby agrees that in connection with the Company’s initial Public Offering and in connection with any Demand Registration, Shelf Offering or Piggyback Registration that is an underwritten Public Offering, not to (i) offer, sell,
contract to sell, pledge or otherwise dispose of (including sales pursuant to Rule 144), directly or indirectly, any equity securities of the Company (including equity securities of the Company that may be deemed to be beneficially owned by such
Holder in accordance with the rules and regulations of the SEC) (collectively, “Securities”), or any securities, options or rights convertible into or exchangeable or exercisable for Securities (collectively, “Other
Securities”), (ii) enter into a transaction which would have the same effect as described in clause (i) above, (iii) enter into any swap, hedge or other arrangement that transfers, in whole or in part, any of the economic consequences
or ownership of any Securities or Other Securities, whether such transaction is to be settled by delivery of such Securities or Other Securities, in cash or otherwise (each of (i), (ii) and (iii) above, a “Sale Transaction”),
or (iv) publicly disclose the intention to enter into any Sale Transaction, commencing on the date on which the Company gives notice to the Holders that a preliminary prospectus has been circulated for such underwritten Public Offering or the
“pricing” of such offering and continuing to the date that is (x) 180 days following the date of the final prospectus for such underwritten Public Offering in the case of the Company’s initial Public Offering, or (y) 90 days
following the date of the final prospectus in the case of any other such underwritten Public Offering (each such period, or such shorter period as agreed to by the managing underwriters, a “Holdback Period”), in each case with such
modifications and exceptions as may be approved by the Majority Investors; provided, that if following any such underwritten offering, the applicable underwriters consent to release any Holder from the requirements of the lock-up agreement entered into (in accordance with this Section 3(a)) between such Holder and such underwriters, with respect to all or a portion of such Holder’s securities covered by such lock-up agreement, such Holder shall not be subject to the restrictions in clauses (i) through (iv) of this paragraph with respect to such securities. The Company may impose stop-transfer instructions with
respect to any Securities or Other Securities subject to the restrictions set forth in this Section 3(a) until the end of such Holdback Period. 

  
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 (b) Company Holdback Agreement. The Company (i) will not file any registration
statement for a Public Offering or cause any such registration statement to become effective, or effect any public sale or distribution of its Securities or Other Securities during any Holdback Period (other than as part of such underwritten Public
Offering, or a registration on Form S-4 or Form S-8 or any successor or similar form which is (x) then in effect or (y) shall become effective upon the
conversion, exchange or exercise of any then outstanding Other Securities) and (ii) will cause each holder of Securities and Other Securities (including each of its directors and executive officers) to agree not to effect any Sale Transaction
during any Holdback Period, except as part of such underwritten registration (if otherwise permitted), unless approved in writing by the Majority Participating Investors and the underwriters managing the Public Offering and to enter into any
customary lock-up, holdback or similar agreements requested by the underwriter(s) managing such offering, in each case with such customary modifications and exceptions as may be approved by the Majority
Participating Investors. 
 Section 4 Registration Procedures. 

(a) Company Obligations. Whenever the Holders have requested that any Registrable Securities be registered pursuant to this Agreement
or have initiated a Shelf Offering, the Company will use its reasonable best efforts to effect the registration and the sale of such Registrable Securities in accordance with the intended method of disposition thereof, and pursuant thereto the
Company will as soon as reasonably practicable: 
 (i) prepare and file with (or submit confidentially to) the SEC a
registration statement, and all amendments and supplements thereto and related prospectuses, with respect to such Registrable Securities and use its reasonable best efforts to cause such registration statement to become effective, all in accordance
with the Securities Act and all applicable rules and regulations promulgated thereunder (provided that before filing or confidentially submitting a registration statement or prospectus or any amendments or supplements thereto, the Company will
furnish to the counsel selected by the Investors covered by such registration statement copies of all such documents proposed to be filed or submitted, which documents will be subject to the review and comment of such counsel); 

(ii) notify each Holder of (A) the issuance by the SEC of any stop order suspending the effectiveness of any registration
statement or the initiation of any proceedings for that purpose, (B) the receipt by the Company or its counsel of any notification with respect to the suspension of the qualification of the Registrable Securities for sale in any jurisdiction or
the initiation or threatening of any proceeding for such purpose, and (C) the effectiveness of each registration statement filed hereunder; 

(iii) prepare and file with the SEC such amendments and supplements to such registration statement and the prospectus used in
connection therewith as may be necessary to keep such registration statement effective for a period ending when all of the securities covered by such registration statement have been disposed of in accordance with

  
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the intended methods of distribution by the sellers thereof set forth in such registration statement (but not in any event before the expiration of any longer period required under the Securities
Act or, if such registration statement relates to an underwritten Public Offering, such longer period as in the opinion of counsel for the underwriters a prospectus is required by law to be delivered in connection with the sale of Registrable
Securities by an underwriter or dealer) and comply with the provisions of the Securities Act with respect to the disposition of all securities covered by such registration statement during such period in accordance with the intended methods of
disposition by the sellers thereof set forth in such registration statement; 
 (iv) furnish, without charge, to each seller
of Registrable Securities thereunder and each underwriter, if any, such number of copies of such registration statement, each amendment and supplement thereto, the prospectus included in such registration statement (including each preliminary
prospectus) (in each case including all exhibits and documents incorporated by reference therein), each amendment and supplement thereto, each Free Writing Prospectus and such other documents as such seller or underwriter, if any, may reasonably
request in order to facilitate the disposition of the Registrable Securities owned by such seller (the Company hereby consenting to the use in accordance with all applicable laws of each such registration statement, each such amendment and
supplement thereto, and each such prospectus (or preliminary prospectus or supplement thereto) or Free Writing Prospectus by each such seller of Registrable Securities and the underwriters, if any, in connection with the offering and sale of the
Registrable Securities covered by such registration statement or prospectus); 
 (v) use its reasonable best efforts to
register or qualify such Registrable Securities under such other securities or blue sky laws of such jurisdictions as any seller reasonably requests and do any and all other acts and things which may be reasonably necessary or advisable to enable
such seller to consummate the disposition in such jurisdictions of the Registrable Securities owned by such seller (provided that the Company will not be required to (A) qualify generally to do business in any jurisdiction where it would
not otherwise be required to qualify but for this subparagraph, (B) consent to general service of process in any such jurisdiction or (C) subject itself to taxation in any such jurisdiction); 

(vi) notify in writing each seller of such Registrable Securities (A) promptly after it receives notice thereof, of the
date and time when such registration statement and each post-effective amendment thereto has become effective or a prospectus or supplement to any prospectus relating to a registration statement has been filed and when any registration or
qualification has become effective under a state securities or blue sky law or any exemption thereunder has been obtained, (B) promptly after receipt thereof, of any request by the SEC for the amendment or supplementing of such registration
statement or prospectus or for additional information, and (C) at any time when a prospectus relating thereto is required to be delivered under the Securities Act, of the happening of any event or of any information or circumstances as a result
of which the prospectus included in such registration statement contains an untrue statement of a material fact or omits any fact necessary to make the statements therein not misleading, and, subject to Section 1(f), if
required by applicable law or to the extent requested by the Majority Participating 

  
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Investors, the Company will use its reasonable best efforts to promptly prepare and file a supplement or amendment to such prospectus so that, as thereafter delivered to the purchasers of such
Registrable Securities, such prospectus will not contain an untrue statement of a material fact or omit to state any fact necessary to make the statements therein not misleading and (D) if at any time the representations and warranties of the
Company in any underwriting agreement, securities sale agreement, or other similar agreement, relating to the offering shall cease to be true and correct; 

(vii) (A) use reasonable best efforts to cause all such Registrable Securities to be listed on each securities exchange on
which similar securities issued by the Company are then listed and, if not so listed, to be listed on a securities exchange and, without limiting the generality of the foregoing, to arrange for at least two market markers to register as such with
respect to such Registrable Securities with FINRA, and (B) comply (and continue to comply) with the requirements of any self-regulatory organization applicable to the Company, including without limitation all corporate governance requirements;

 (viii) provide a transfer agent and registrar for all such Registrable Securities and a CUSIP number for all such
Registrable Securities, not later than the effective date of such registration statement; 
 (ix) enter into and perform such
customary agreements (including, as applicable, underwriting agreements in customary form) and take all such other reasonable actions as the Majority Participating Investors or the underwriters, if any, reasonably request in order to expedite or
facilitate the disposition of such Registrable Securities (including, without limitation, making available the executive officers of the Company and participating in “road shows,” investor presentations, marketing events and other selling
efforts and effecting a stock or unit split or combination, recapitalization or reorganization); 
 (x) make available for
inspection by any seller of Registrable Securities, any underwriter participating in any disposition or sale pursuant to such registration statement and any attorney, accountant or other agent retained by any such seller or underwriter, all
financial and other records, pertinent corporate and business documents and properties of the Company as will be necessary to enable them to exercise their due diligence responsibility, and cause the Company’s officers, directors, employees,
agents, representatives and independent accountants to supply all information reasonably requested by any such seller, underwriter, attorney, accountant or agent in connection with such registration statement and the disposition of such Registrable
Securities pursuant thereto; 
 (xi) take all reasonable actions to ensure that any Free Writing Prospectus utilized in
connection with any Demand Registration or Piggyback Registration or Shelf Offering hereunder complies in all material respects with the Securities Act, is filed in accordance with the Securities Act to the extent required thereby, is retained in
accordance with the Securities Act to the extent required thereby and, when taken together with the related prospectus, prospectus supplement and related documents, will not contain any untrue statement of a material fact or omit to state a material
fact necessary to make the statements therein, in light of the circumstances under which they were made, not misleading; 

  
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 (xii) otherwise use its reasonable best efforts to comply with all
applicable rules and regulations of the SEC, and make available to its security holders, as soon as reasonably practicable, an earnings statement covering the period of at least twelve (12) months beginning with the first day of the
Company’s first full calendar quarter after the effective date of the registration statement, which earnings statement will satisfy the provisions of Section 11(a) of the Securities Act and Rule 158 thereunder; 

(xiii) permit any Holder which, in its sole and exclusive judgment, might be deemed to be an underwriter or a controlling
person of the Company, to participate in the preparation of such registration or comparable statement and to allow such Holder to provide language for insertion therein, in form and substance satisfactory to the Company, which in the reasonable
judgment of such Holder and its counsel should be included; 
 (xiv) use reasonable best efforts to (A) make Short-Form
Registration available for the sale of Registrable Securities and (B) prevent the issuance of any stop order suspending the effectiveness of a registration statement, or the issuance of any order suspending or preventing the use of any related
prospectus or suspending the qualification of any Common Equity included in such registration statement for sale in any jurisdiction use, and in the event any such order is issued, reasonable best efforts to obtain promptly the withdrawal of such
order; 
 (xv) use its reasonable best efforts to cause such Registrable Securities covered by such registration
statement to be registered with or approved by such other governmental agencies or authorities as may be necessary to enable the sellers thereof to consummate the disposition of such Registrable Securities; 

(xvi) cooperate with the Holders covered by the registration statement and the managing underwriter or agent, if any, to
facilitate the timely preparation and delivery of certificates (not bearing any restrictive legends) representing securities to be sold under the registration statement, or the removal of any restrictive legends associated with any account at which
such securities are held, and enable such securities to be in such denominations and registered in such names as the managing underwriter, or agent, if any, or such Holders may request; 

(xvii) if requested by any managing underwriter, include in any prospectus or prospectus supplement updated financial or
business information for the Company’s most recent period or current quarterly period (including estimated results or ranges of results) if required for purposes of marketing the offering in the view of the managing underwriter; 

(xviii) take no direct or indirect action prohibited by Regulation M under the Exchange Act; provided, however,
that to the extent that any prohibition is applicable to the Company, the Company will take such action as is necessary to make any such prohibition inapplicable; 

  
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 (xix) (A) cooperate with each Holder covered by the registration statement
and each underwriter or agent participating in the disposition of such Registrable Securities and their respective counsel in connection with the preparation and filing of applications, notices, registrations and responses to requests for additional
information with FINRA, the New York Stock Exchange, Nasdaq Stock Market or any other national securities exchange on which the Common Equity is or is to be listed, and (B) to the extent required by the rules and regulations of FINRA, retain a
Qualified Independent Underwriter acceptable to the managing underwriter; 
 (xx) in the case of any underwritten
offering, use its reasonable best efforts to obtain, and deliver to the underwriter(s), in the manner and to the extent provided for in the applicable underwriting agreement, one or more cold comfort letters from the Company’s
independent public accountants in customary form and covering such matters of the type customarily covered by cold comfort letters delivered to underwriters in an underwritten offering; 

(xxi) use its reasonable best efforts to provide (A) a legal opinion of the Company’s outside counsel dated the
effective date of such registration statement addressed to the Company addressing the validity of the Registrable Securities being offered thereby, (B) on the date that such Registrable Securities are delivered to the underwriters for sale in
connection with a Demand Registration or Shelf Offering, if such securities are being sold through underwriters, or, if such securities are not being sold through underwriters, on the closing date of the applicable sale, (1) one or more legal
opinions of the Company’s outside counsel, dated such date, in form and substance as customarily given to underwriters in an underwritten public offering or, in the case of a non-underwritten offering, to
the broker, placement agent or other agent of the Holders assisting in the sale of the Registrable Securities and (2) one or more “negative assurances letters” of the Company’s outside counsel, dated such date, in form and
substance as is customarily given to underwriters in an underwritten public offering or, in the case of a non-underwritten offering, to the broker, placement agent or other agent of the Holders assisting in
the sale of the Registrable Securities, in each case, addressed to the underwriters, if any, or, if requested, in the case of a non-underwritten offering, to the broker, placement agent or other agent of the
Holders assisting in the sale of the Registrable Securities and (C) customary certificates executed by authorized officers of the Company as may be reasonably requested by any Holder or any underwriter of such Registrable Securities; 

(xxii) if the Company does not pay the filing fee covering the Registrable Securities at the time an Automatic Shelf
Registration Statement is filed, pay such fee at such time or times as the Registrable Securities are to be sold; and 

(xxiii) if a Shelf Registration Statement has been outstanding for at least three (3) years, at the end of the third year,
refile a new Shelf Registration Statement covering the Registrable Securities, and, with respect to an Automatic Shelf Registration Statement, if at any time when the Company is required to re-evaluate its
WKSI status the Company determines that it is not a WKSI, use its reasonable best efforts to refile the Shelf Registration Statement on Form S-3 and, if such form is not available, Form S-1 and keep such registration statement effective during the period during which such registration statement is required to be kept effective. 

  
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 (b) Officer Obligations. Each Holder that is an officer of the Company agrees that if
and for so long as he or she is employed by the Company or any Subsidiary thereof, he or she will participate fully in the sale process in a manner customary for persons in like positions and consistent with his or her other duties with the Company,
including the preparation of the registration statement and the preparation and presentation of any road shows. 
 (c) Automatic Shelf
Registration Statements. If the Company files any Automatic Shelf Registration Statement for the benefit of the holders of any of its securities other than the Holders, and the Investors do not request that their Registrable Securities be
included in such Shelf Registration Statement, the Company agrees that, at the request of any Investor, it will include in such Automatic Shelf Registration Statement such disclosures as may be required by Rule 430B in order to ensure that the
Investors may be added to such Shelf Registration Statement at a later time through the filing of a prospectus supplement rather than a post-effective amendment. If the Company has filed any Automatic Shelf Registration Statement for the benefit of
the holders of any of its securities other than the Holders, the Company shall, at the request of any Investor, file any post-effective amendments necessary to include therein all disclosure and language necessary to ensure that the holders of
Registrable Securities may be added to such Shelf Registration Statement. 
 (d) Additional Information. The Company may require each
seller of Registrable Securities as to which any registration is being effected to furnish the Company such information regarding such seller and the distribution of such securities as the Company may from time to time reasonably request in writing,
as a condition to such seller’s participation in such registration. 
 (e) In-Kind
Distributions. If any Investor (and/or any of their Affiliates) seeks to effectuate an in-kind distribution of all or part of their Registrable Securities to their respective direct or indirect
equityholders, the Company will, subject to any applicable lock-ups, work with the foregoing Persons to facilitate such in-kind distribution in the manner reasonably
requested and consistent with the Company’s obligations under the Securities Act. 
 (f) Suspended Distributions. Each
Person participating in a registration hereunder agrees that, upon receipt of any notice from the Company of the happening of any event of the kind described in Section 4(a)(vi), such Person will immediately discontinue the
disposition of its Registrable Securities pursuant to the registration statement until such Person’s receipt of the copies of a supplemented or amended prospectus as contemplated by Section 4(a)(vi), subject to the
Company’s compliance with its obligations under Section 4(a)(vi). 
 (g) Other. To the extent that any
of the Participating Investors is or may be deemed to be an “underwriter” of Registrable Securities pursuant to any SEC comments or policies, the Company agrees that (i) the indemnification and contribution provisions contained in
Section 6 shall be applicable to the benefit of such Participating Investor in their role as an underwriter or deemed underwriter in addition to their capacity as a holder and (ii) such Participating Investor shall be
entitled to conduct the due diligence which they would normally conduct in connection with an offering of securities registered under the Securities Act, including without limitation receipt of customary opinions and comfort letters addressed to
such Participating Investor. 

  
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 Section 5 Registration Expenses. Except as expressly provided herein, all out-of-pocket expenses incurred by the Company in connection with the performance of or compliance with this Agreement and/or in connection with any Demand Registration,
Piggyback Registration or Shelf Offering, whether or not the same shall become effective, shall be paid by the Company, including, without limitation: (i) all registration and filing fees, and any other fees and expenses associated with filings
required to be made with the SEC or FINRA, (ii) all fees and expenses in connection with compliance with any securities or “blue sky” laws, (iii) all printing, duplicating, word processing, messenger, telephone, facsimile and
delivery expenses (including expenses of printing certificates for the Registrable Securities in a form eligible for deposit with The Depository Trust Company or other depositary and of printing prospectuses and Company Free Writing Prospectuses),
(iv) all fees and disbursements of counsel for the Company and of all independent certified public accountants of the Company (including the expenses of any special audit and cold comfort letters required by or incident to such performance), (v)
Securities Act liability insurance or similar insurance if the Company so desires or the underwriters so require in accordance with then-customary underwriting practice, (vi) all fees and expenses incurred in connection with the listing of the
Registrable Securities on any securities exchange on which similar securities of the Company are then listed (or on which exchange the Registrable Securities are proposed to be listed in the case of the Company’s initial Public Offering), (vii)
all applicable rating agency fees with respect to the Registrable Securities, (viii) all reasonable and documented fees and disbursements of one legal counsel for each of General Atlantic and Summit, in each case selected by General Atlantic or
Summit, as applicable, together with any one necessary local counsel as may be required by the Investors or the managing underwriters, (ix) any other fees or expenses incurred by the Investors in connection with the exercise of their rights
under this agreement, provided that the Company shall only be required to pay such fees and expenses in an amount that does not exceed $20,000 in the aggregate, (x) any fees and disbursements of underwriters customarily paid by issuers or
sellers of securities, (xi) all fees and expenses of any special experts or other Persons retained by the Company or the Investors in connection with any Registration, (xii) all of the Company’s internal expenses (including all
salaries and expenses of its officers and employees performing legal or accounting duties) and (xiii) all expenses related to the “road-show” for any underwritten offering, including all travel, meals and lodging. All such expenses
are referred to herein as “Registration Expenses.” The Company shall not be required to pay, and each Person that sells securities pursuant to a Demand Registration, Shelf Offering or Piggyback Registration hereunder will bear and
pay, all underwriting discounts and commissions applicable to the Registrable Securities sold for such Person’s account and all transfer taxes (if any) attributable to the sale of Registrable Securities. 

Section 6 Indemnification and Contribution. 

(a) By the Company. The Company will indemnify and hold harmless, to the fullest extent permitted by law and without limitation as to
time, each Holder, such Holder’s officers, directors, employees, agents, fiduciaries, stockholders, managers, partners, members, affiliates, direct and indirect equityholders, consultants and representatives, and any successors and assigns
thereof, and each Person who controls such Holder (within the meaning of the 

  
 -14- 

 
Securities Act) (the “Indemnified Parties”) against all losses, claims, actions, damages, liabilities and expenses (including with respect to actions or proceedings, whether
commenced or threatened, and including reasonable attorney fees and expenses) (collectively, “Losses”) caused by, resulting from, arising out of, based upon or related to any of the following (each, a “Violation”)
by the Company: (i) any untrue or alleged untrue statement of material fact contained in (A) any registration statement, prospectus, preliminary prospectus or Free Writing Prospectus, or any amendment thereof or supplement thereto or
(B) any application or other document or communication (in this Section 6, collectively called an “application”) executed by or on behalf of the Company or based upon written information furnished by
or on behalf of the Company filed in any jurisdiction in order to qualify any securities covered by such registration under the “blue sky” or securities laws thereof, (ii) any omission or alleged omission of a material fact required
to be stated therein or necessary to make the statements therein not misleading or (iii) any violation or alleged violation by the Company of the Securities Act or any other similar federal or state securities laws or any rule or regulation
promulgated thereunder applicable to the Company and relating to action or inaction required of the Company in connection with any such registration, qualification or compliance. In addition, the Company will reimburse such Indemnified Party for any
legal or any other expenses reasonably incurred by them in connection with investigating or defending any such Losses. Notwithstanding the foregoing, the Company will not be liable in any such case to the extent that any such Losses result from,
arise out of, are based upon, or relate to an untrue statement, or omission, made in such registration statement, any such prospectus, preliminary prospectus or Free Writing Prospectus or any amendment or supplement thereto, or in any application,
in reliance upon, and in conformity with, written information prepared and furnished in writing to the Company by such Indemnified Party expressly for use therein or by such Indemnified Party’s failure to deliver a copy of the registration
statement or prospectus or any amendments or supplements thereto after the Company has furnished such Indemnified Party with a sufficient number of copies of the same. In connection with an underwritten offering, the Company will indemnify such
underwriters, their officers and directors, and each Person who controls such underwriters (within the meaning of the Securities Act) to the same extent as provided above with respect to the indemnification of the Indemnified Parties or as otherwise
agreed to in the underwriting agreement executed in connection with such underwritten offering. Such indemnity and reimbursement of expenses shall remain in full force and effect regardless of any investigation made by or on behalf of such
Indemnified Party and shall survive the transfer of such securities by such seller. 
 (b) By Holders. In connection with any
registration statement in which a Holder is participating, each such Holder will furnish to the Company in writing such information regarding such Holder as the Company reasonably requests for use in connection with any such registration statement
or prospectus and, to the extent permitted by law, will indemnify the Company, its officers, directors, employees, agents and representatives, and each Person who controls the Company (within the meaning of the Securities Act) against any Losses
resulting from (as determined by a final and appealable judgment, order or decree of a court of competent jurisdiction) any untrue or alleged untrue statement of material fact contained in the registration statement, prospectus or preliminary
prospectus or any amendment thereof or supplement thereto or any omission or alleged omission of a material fact required to be stated therein or necessary to make the statements therein not misleading, but only to the extent that such untrue
statement or omission is contained in any information so furnished in writing by such Holder expressly for use therein; provided that the obligation to indemnify will be individual, not joint and several, for each Holder and each
Holder’s liability pursuant to the indemnification and contribution provisions herein will be limited to the net amount of proceeds received by such Holder from the sale of Registrable Securities pursuant to such registration statement. 

  
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 (c) Claim Procedure. Any Person entitled to indemnification hereunder will
(i) give prompt written notice to the indemnifying party of any claim with respect to which it seeks indemnification (provided that the failure to give prompt notice will impair any Person’s right to indemnification hereunder only
to the extent such failure has prejudiced the indemnifying party) and (ii) unless in such indemnified party’s reasonable judgment a conflict of interest between such indemnified and indemnifying parties may exist with respect to such
claim, permit such indemnifying party to assume the defense of such claim with counsel reasonably satisfactory to the indemnified party. If such defense is assumed, the indemnifying party will not be subject to any liability for any settlement made
by the indemnified party without its consent (but such consent will not be unreasonably withheld, conditioned or delayed). An indemnifying party who is not entitled to, or elects not to, assume the defense of a claim will not be obligated to pay the
fees and expenses of more than one counsel for all parties indemnified by such indemnifying party with respect to such claim, unless in the reasonable judgment of any indemnified party a conflict of interest may exist between such indemnified party
and any other of such indemnified parties with respect to such claim. In such instance, the conflicted indemnified parties will have a right to retain one separate counsel, chosen by the majority of the conflicted indemnified parties involved in the
indemnification and approved by the Majority Investors, at the expense of the indemnifying party, which approval shall not be unreasonably withheld, conditioned or delayed. 

(d) Contribution. If the indemnification provided for in this Section 6 is held by a court of competent
jurisdiction to be unavailable to, or is insufficient to hold harmless, an indemnified party or is otherwise unenforceable with respect to any Loss referred to herein, then such indemnifying party will contribute to the amounts paid or payable by
such indemnified party as a result of such Loss, (i) in such proportion as is appropriate to reflect the relative fault of the indemnifying party on the one hand and of the indemnified party on the other hand in connection with the statements
or omissions which resulted in such Loss as well as any other relevant equitable considerations or (ii) if the allocation provided by clause (i) of this Section 6(d) is not permitted by applicable law, then in
such proportion as is appropriate to reflect not only such relative fault but also the relative benefit of the Company on the one hand and of the sellers of Registrable Securities and any other sellers participating in the registration statement on
the other in connection with the statement or omissions which resulted in such Losses, as well as any other relevant equitable considerations; provided that the maximum amount of liability in respect of the indemnification and contribution
provisions herein will be limited, in the case of each seller of Registrable Securities, to an amount equal to the net proceeds actually received by such seller from the sale of Registrable Securities effected pursuant to such registration. The
relative fault of the indemnifying party and of the indemnified party will be determined by reference to, among other things, whether the untrue (or, as applicable alleged) untrue statement of a material fact or the omission to state a material fact
relates to information supplied by the indemnifying party or by the indemnified party and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The parties hereto agree
that it would not be just or equitable if the contribution pursuant to this Section 6(d) were to be determined by pro rata allocation or by any other method of allocation that does not take into account such equitable
considerations. The amount paid or payable by an indemnified party as a result of the 

  
 -16- 

 
Losses referred to herein will be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending against any action or
claim which is the subject hereof. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) will be entitled to contribution from any Person who is not guilty of such fraudulent
misrepresentation. 
 (e) Indemnification Priority. The Company hereby acknowledges and agrees that any of the Persons entitled to
indemnification and contribution pursuant to this Section 6 (each, a “Company Indemnitee” and collectively, the “Company Indemnitees”) may have certain rights to indemnification,
advancement of expenses and/or insurance provided by other sources. The Company hereby acknowledges and agrees (i) that it is the indemnitor of first resort (i.e., its obligations to a Company Indemnitee are primary and any obligation of such
other sources to advance expenses or to provide indemnification for the same expenses or liabilities incurred by such Company Indemnitee are secondary) and (ii) that it shall be required to advance the full amount of expenses incurred by a
Company Indemnitee and shall be liable for the full amount of all expenses, judgments, penalties, fines and amounts paid in settlement to the extent legally permitted and as required by the terms of this Agreement without regard to any rights a
Company Indemnitee may have against such other sources. The Company further agrees that no advancement or payment by such other sources on behalf of a Company Indemnitee with respect to any claim for which such Company Indemnitee has sought
indemnification, advancement of expenses or insurance from the Company shall affect the foregoing, and that such other sources shall have a right of contribution and/or be subrogated to the extent of such advancement or payment to all of the rights
of recovery of such Company Indemnitee against the Company. 
 (f) Release. No indemnifying party will, except with the consent of
the indemnified party, consent to the entry of any judgment or enter into any settlement that does not include as an unconditional term thereof giving by the claimant or plaintiff to such indemnified party of a release from all liability in respect
to such claim or litigation. 
 (g) Non-exclusive Remedy; Survival. The indemnification and
contribution provided for under this Agreement will be in addition to any other rights to indemnification or contribution that any indemnified party may have pursuant to law or contract (and the Company and its Subsidiaries shall be considered the
indemnitors of first resort in all such circumstances to which this Section 6 applies) and will remain in full force and effect regardless of any investigation made by or on behalf of the indemnified party or any officer,
director or controlling Person of such indemnified party and will survive the transfer of Registrable Securities and the termination or expiration of this Agreement. 

Section 7 Cooperation with Underwritten Offerings. No Person may participate in any underwritten registration hereunder unless
such Person (i) agrees to sell such Person’s securities on the basis provided in any underwriting arrangements approved by the Person or Persons entitled hereunder to approve such arrangements (including, without limitation, pursuant to
the terms of any over-allotment or “green shoe” option requested by the underwriters; provided that no Holder will be required to sell more than the number of Registrable Securities such Holder has requested to include in such
registration) and (ii) completes, executes and delivers all questionnaires, powers of attorney, stock powers, custody agreements, indemnities, underwriting agreements and other documents and agreements required under the terms of such
underwriting 

  
 -17- 

 
arrangements or as may be reasonably requested by the Company and the lead managing underwriter(s). To the extent that any such agreement is entered into pursuant to, and consistent with,
Section 3, Section 4 and/or this Section 7, the respective rights and obligations created under such agreement will supersede the respective rights and obligations of the
Holders, the Company and the underwriters created thereby with respect to such registration. 
 Section 8 Subsidiary Public
Offering. If, after an initial Public Offering of the common equity securities of one of its Subsidiaries, the Company distributes securities of such Subsidiary to its equityholders, then the rights and obligations of the Company pursuant to
this Agreement will apply, mutatis mutandis, to such Subsidiary, and the Company will cause such Subsidiary to comply with such Subsidiary’s obligations under this Agreement as if it were the Company hereunder. 

Section 9 Joinder. The Company may from time to time (with the prior written consent of the Majority Investors, except as provided
in Section 10(e) and which consent shall not be unreasonably withheld, conditioned or delayed) permit any Person who acquires Common Equity (or rights to acquire Common Equity) to become a party to this Agreement and to be entitled to and be
bound by all of the rights and obligations as a Holder by obtaining an executed Joinder to this Agreement from such Person in the form of Exhibit B attached hereto (a “Joinder”). Subject to
Section 10(c), upon the execution and delivery of a Joinder by such Person, the Common Equity held by such Person shall become the category of Registrable Securities (i.e. Investor or Other Holder Registrable Securities)
and such Person shall be deemed the category of Holder (i.e. Investor or Other Holder), in each case as set forth on the signature page to such Joinder. 

Section 10 General Provisions. 

(a) Amendments and Waivers. Except as otherwise provided herein, the provisions of this Agreement may be amended, modified or waived
only with the prior written consent of the Company and each of the Majority Investors; provided that no such amendment, modification or waiver that would (i) treat a specific Holder or group of Holders of Registrable Securities (i.e.,
Other Holders) in a manner materially and adversely different than any other Holder or group of Holders or (ii) materially and adversely change a specific right granted to such Holder or group by name, will be effective against such
Holder or group of Holders without the consent of the holders of a majority of the Registrable Securities that are held by the group of Holders that is materially and adversely affected thereby; provided further that the foregoing provision shall
not apply to any amendments or modifications otherwise expressly permitted by this Agreement, including any required to add a party hereto. The failure or delay of any Person to enforce any of the provisions of this Agreement will in no way be
construed as a waiver of such provisions and will not affect the right of such Person thereafter to enforce each and every provision of this Agreement in accordance with its terms. A waiver or consent to or of any breach or default by any Person in
the performance by that Person of his, her or its obligations under this Agreement will not be deemed to be a consent or waiver to or of any other breach or default in the performance by that Person of the same or any other obligations of that
Person under this Agreement. 

  
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 (b) Remedies. The parties to this Agreement will be entitled to enforce their rights
under this Agreement specifically (without posting a bond or other security), to recover damages caused by reason of any breach of any provision of this Agreement and to exercise all other rights existing in their favor. The parties hereto agree and
acknowledge that a breach of this Agreement would cause irreparable harm and money damages would not be an adequate remedy for any such breach and that, in addition to any other rights and remedies existing hereunder, any party will be entitled to
specific performance and/or other injunctive relief from any court of law or equity of competent jurisdiction (without posting any bond or other security) in order to enforce or prevent violation of the provisions of this Agreement. 

(c) Severability. Whenever possible, each provision of this Agreement will be interpreted in such manner as to be effective and valid
under applicable law, but if any provision of this Agreement is held to be prohibited, invalid, illegal or unenforceable in any respect under any applicable law or regulation in any jurisdiction, such prohibition, invalidity, illegality or
unenforceability will not affect the validity, legality or enforceability of any other provision of this Agreement in such jurisdiction or in any other jurisdiction, but this Agreement will be reformed, construed and enforced in such jurisdiction as
if such prohibited, invalid, illegal or unenforceable provision had never been contained herein. 
 (d) Entire Agreement. Except as
otherwise provided herein, this Agreement contains the complete agreement and understanding among the parties hereto with respect to the subject matter hereof and supersedes and preempts any prior understandings, agreements or representations by or
among the parties hereto, written or oral, which may have related to the subject matter hereof in any way. 
 (e) Successors and
Assigns. Except as otherwise provided herein, this Agreement will bind and inure to the benefit and be enforceable by the Company and its successors and permitted assigns and the Holders. 

(d) Notices. Any notice, demand or other communication to be given under or by reason of the provisions of this Agreement will be in
writing and will be deemed to have been given (i) when delivered personally to the recipient, (ii) when sent by confirmed electronic mail or facsimile if sent during normal business hours of the recipient; but if not, then on the next
Business Day, (iii) one Business Day after it is sent to the recipient by reputable overnight courier service (charges prepaid) or (iv) three Business Days after it is mailed to the recipient by first class mail, return receipt requested.
Such notices, demands and other communications will be sent to the Company at the address specified on the signature page hereto or any Joinder and to any holder, or at such address or to the attention of such other Person as the recipient party has
specified by prior written notice to the sending party. Any party may change such party’s address for receipt of notice by giving prior written notice of the change to the sending party as provided herein. The Company’s address is: 

EngageSmart, Inc. 
 30 Braintree
Hl, Office Park, Ste 101 
 Braintree, MA 02184 

Attention: General Counsel 

Email: ckallenbach@engagesmart.com 

  
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 With a copy to: 

Latham & Watkins LLP 

1271 Avenue of the Americas 
 New
York, NY 10020 
 Attention: 

Ian D. Schuman 
 Stelios G.
Saffos 
 Brittany D. Ruiz 

Email: 
 ian.schuman@lw.com 

stelios.saffos@lw.com 

brittany.ruiz@lw.com 
 or to such other address
or to the attention of such other person as the recipient party has specified by prior written notice to the sending party. Any request or consent made under this Agreement must be in writing (electronic mail will suffice). 

(e) Business Days. If any time period for giving notice or taking action hereunder expires on a day that is not a Business Day, the
time period will automatically be extended to the Business Day immediately following such Saturday, Sunday or legal holiday. 
 (f)
Governing Law. The corporate law of the State of Delaware will govern all issues and questions concerning the relative rights of the Company and its equityholders. All issues and questions concerning the construction, validity, interpretation
and enforcement of this Agreement and the exhibits and schedules hereto will be governed by, and construed in accordance with, the laws of the State of Delaware, without giving effect to any choice of law or conflict of law rules or provisions
(whether of the State of Delaware or any other jurisdiction) that would cause the application of the laws of any jurisdiction other than the State of Delaware. 

(g) MUTUAL WAIVER OF JURY TRIAL. AS A SPECIFICALLY BARGAINED FOR INDUCEMENT FOR EACH OF THE PARTIES HERETO TO ENTER INTO THIS AGREEMENT
(AFTER HAVING THE OPPORTUNITY TO CONSULT WITH COUNSEL), EACH PARTY HERETO EXPRESSLY WAIVES THE RIGHT TO TRIAL BY JURY IN ANY LAWSUIT OR PROCEEDING RELATING TO OR ARISING IN ANY WAY FROM THIS AGREEMENT OR THE MATTERS CONTEMPLATED HEREBY. 

(h) CONSENT TO JURISDICTION AND SERVICE OF PROCESS. EACH OF THE PARTIES IRREVOCABLY SUBMITS TO THE
NON-EXCLUSIVE JURISDICTION OF THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF DELAWARE, FOR THE PURPOSES OF ANY SUIT, ACTION OR OTHER PROCEEDING ARISING OUT OF THIS AGREEMENT, ANY RELATED AGREEMENT OR ANY
TRANSACTION CONTEMPLATED HEREBY OR THEREBY. EACH OF THE PARTIES HERETO FURTHER AGREES THAT SERVICE OF ANY PROCESS, SUMMONS, NOTICE OR DOCUMENT BY U.S. REGISTERED MAIL TO SUCH PARTY’S RESPECTIVE ADDRESS SET FORTH ABOVE WILL BE EFFECTIVE SERVICE
OF PROCESS FOR ANY ACTION, SUIT OR PROCEEDING WITH RESPECT TO ANY MATTERS TO WHICH IT HAS SUBMITTED TO JURISDICTION IN THIS PARAGRAPH. EACH OF THE PARTIES HERETO IRREVOCABLY AND UNCONDITIONALLY WAIVES ANY OBJECTION TO THE

  
 -20- 

 
LAYING OF VENUE OF ANY ACTION, SUIT OR PROCEEDING ARISING OUT OF THIS AGREEMENT, ANY RELATED DOCUMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY AND THEREBY IN THE UNITED STATES DISTRICT COURT FOR
THE DISTRICT OF DELAWARE, AND HEREBY AND THEREBY FURTHER IRREVOCABLY AND UNCONDITIONALLY WAIVES AND AGREES NOT TO PLEAD OR CLAIM IN ANY SUCH COURT THAT ANY SUCH ACTION, SUIT OR PROCEEDING BROUGHT IN ANY SUCH COURT HAS BEEN BROUGHT IN AN INCONVENIENT
FORUM. 
 (i) No Recourse. Notwithstanding anything to the contrary in this Agreement, the Company and each Holder agrees and
acknowledges that no recourse under this Agreement or any documents or instruments delivered in connection with this Agreement, will be had against any current or future director, officer, employee, general or limited partner or member of any Holder
or any Affiliate or assignee thereof, whether by the enforcement of any assessment or by any legal or equitable proceeding, or by virtue of any statute, regulation or other applicable law, it being expressly agreed and acknowledged that no personal
liability whatsoever will attach to, be imposed on or otherwise be incurred by any current or future officer, agent or employee of any Holder or any current or future member of any Holder or any current or future director, officer, employee, partner
or member of any Holder or of any Affiliate or assignee thereof, as such for any obligation of any Holder under this Agreement or any documents or instruments delivered in connection with this Agreement for any claim based on, in respect of or by
reason of such obligations or their creation. 
 (j) Descriptive Headings; Interpretation. The descriptive headings of this Agreement
are inserted for convenience only and do not constitute a part of this Agreement. The use of the word “including” in this Agreement will be by way of example rather than by limitation. 

(k) No Strict Construction. The language used in this Agreement will be deemed to be the language chosen by the parties hereto to
express their mutual intent, and no rule of strict construction will be applied against any party. 
 (l) Counterparts. This
Agreement may be executed in multiple counterparts, any one of which need not contain the signature of more than one party, but all such counterparts taken together will constitute one and the same agreement. 

(m) Electronic Delivery. This Agreement, the agreements referred to herein, and each other agreement or instrument entered into in
connection herewith or therewith or contemplated hereby or thereby, and any amendments hereto or thereto, to the extent executed and delivered by means of a photographic, photostatic, facsimile or similar reproduction of such signed writing using a
facsimile machine or electronic mail will be treated in all manner and respects as an original agreement or instrument and will be considered to have the same binding legal effect as if it were the original signed version thereof delivered in
person. At the request of any party hereto or to any such agreement or instrument, each other party hereto or thereto will re-execute original forms thereof and deliver them to all other parties. No party
hereto or to any such agreement or instrument will raise the use of a facsimile machine or electronic mail to deliver a signature or the fact that any signature or agreement or instrument was transmitted or communicated through the use of a
facsimile machine or electronic mail as a defense to the formation or enforceability of a contract and each such party forever waives any such defense. 

  
 -21- 

 (n) Further Assurances. In connection with this Agreement and the transactions
contemplated hereby, each Holder agrees to execute and deliver any additional documents and instruments and perform any additional acts that may be necessary or appropriate to effectuate and perform the provisions of this Agreement and the
transactions contemplated hereby. 
 (o) Dividends, Recapitalizations, Etc. If at any time or from time to time there is any change
in the capital structure of the Company by way of a stock split, stock dividend, distribution, combination or reclassification, or through a merger, consolidation, reorganization or recapitalization, or by any other means, appropriate adjustment
will be made in the provisions hereof so that the rights and privileges granted hereby will continue. 
 (p) No Third-Party
Beneficiaries. No term or provision of this Agreement is intended to be, or shall be, for the benefit of any Person not a party hereto, and no such other Person shall have any right or cause of action hereunder, except as otherwise expressly
provided herein. 
 (q) Current Public Information. At all times after the Company has filed a registration statement with the SEC
pursuant to the requirements of either the Securities Act or the Exchange Act, the Company will file all reports required to be filed by it under the Securities Act and the Exchange Act and will take such further action as any Investor may
reasonably request, all to the extent required to enable such Holders to sell Registrable Securities (or securities that would be Registrable Securities but for the final sentence of the definition of Registrable Securities) pursuant to Rule 144.

 *    *    *    *    * 

  
 -22- 

 IN WITNESS WHEREOF, the parties have executed this Registration Rights Agreement as of the
date first written above. 
  

			
	ENGAGESMART, INC.
		
	By:	 	 
		 	Name:
		 	Title:

 [Signature Page to Stockholders Agreement] 

 
			
	GENERAL ATLANTIC (IC), L.P.
	
	By: General Atlantic (SPV) GP, LLC, its general partner
	
	By: General Atlantic, L.P., its sole member
		
	By:	 	 

 
			
	Name:	 	
	Title:	 	

 [Signature Page to Stockholders Agreement] 

 
			
	SUMMIT PARTNERS GROWTH EQUITY FUND VIII-A, L.P.
	
	By: Summit Partners GE VIII, L.P.
	Its: General Partner
	
	By: Summit Partners GE VIII, LLC
	Its: General Partner
		
	By:	 	 
	Name:
	Title:

  

			
	SUMMIT PARTNERS GROWTH EQUITY FUND VIII-B, L.P.
	
	By: Summit Partners GE VIII, L.P.
	Its: General Partner
	
	By: Summit Partners GE VIII, LLC
	Its: General Partner
		
	By:	 	 
	Name:
	Title:

  

			
	SUMMIT PARTNERS ENTREPRENEUR ADVISORS FUND L.P.
	
	By: Summit Partners Entrepreneur Advisors GP, LLC
	Its: General Partner
	
	By: Summit Master Company, LLC
	Its: Sole Member
		
	By:	 	 
	Name:
	Title:

 [Signature Page to Stockholders Agreement] 

 
			
	SUMMIT INVESTORS I, LLC
	
	By: Summit Investors Management, LLC
	Its: Manager
	
	By: Summit Partners, L.P.
	Its: Manager
	
	By: Summit Master Company, LLC
	Its: General Partner
		
	By:	 	 
	Name:
	Title:

  

			
	SUMMIT INVESTORS I (UK), L.P.
	
	By: Summit Investors Management, LLC
	Its: General Partner
	
	By: Summit Partners, L.P.
	Its: Manager
	
	By: Summit Master Company, LLC
	Its: General Partner
		
	By:	 	 
	Name:
	Title:

 [Signature Page to Stockholders Agreement] 

 
			
	INVESTORS:
	
	ROBERT P. BENNETT
		
	By:	 	 

 [Signature Page to Stockholders Agreement] 

 
			
	 ROBERT P. BENNETT 2019

DESCENDANTS’ TRUST

 
			
		
	By:	 	 

 
			
	Name:	 	John Burgess
	Title:	 	Trustee

 [Signature Page to Stockholders Agreement] 

 
			
	 THE BENNETT FAMILY 2020 TRUST

 
			
		
	By:	 	 

 
			
	Name:	 	John Burgess
	Title:	 	Trustee

 [Signature Page to Stockholders Agreement] 

 
			
	 THE ROBERT P. BENNETT 2020 GRANTOR
RETAINED ANNUITY
TRUST

 
			
		
	By:	 	 

 
			
	Name:	 	Robert P. Bennett
	Title:	 	Trustee

 [Signature Page to Stockholders Agreement] 

 
			
	 JOHN BURGESS

 
			
		
	By:	 	 

[Signature Page to Stockholders Agreement] 

 
			
	 JOHN MORABITO

 
			
		
	By:	 	 

[Signature Page to Stockholders Agreement] 

 
			
	 JOHN MORABITO 2019

DESCENDANTS’ TRUST

 
			
		
	By:	 	 

 
			
	Name:	 	John Termini
	Title:	 	Trustee

 [Signature Page to Stockholders Agreement] 

 
			
	MARIA MORABITO
		
	By:	 	 

  
 [Signature Page to
Stockholders Agreement] 

 
			
	KELTON AVERYT 2019
	DESCENDANTS’ TRUST
		
	By:	 	 
	Name: Aaron Hall
	Title:   Trustee

  
 [Signature Page to
Stockholders Agreement] 

 
			
	QUITO BELLA FAMILY TRUST
		
	By:	 	 
	Name: Kelton Averyt
	Title:   Trustee

  
 [Signature Page to
Stockholders Agreement] 

 
			
	ROBERT LAPIDES
		
	By:	 	 

  
 [Signature Page to
Stockholders Agreement] 

 
			
	ROBERT LAPIDES 2019
	DESCENDANTS’ TRUST
		
	By:	 	 
	Name: John Callahan
	Title:   Trustee

  
 [Signature Page to
Stockholders Agreement] 

 
			
	ROBERT LAPIDES 2019 TRUST
		
	By:	 	 
	Name: Robert Lapides
	Title:   Trustee

  
 [Signature Page to
Stockholders Agreement] 

 
			
	HOWARD SPECTOR
		
	 By:
	 	 

  
 [Signature Page
to Stockholders Agreement] 

 
			
	 HOWARD SPECTOR 2021

IRREVOCABLE TRUST

 
			
		
	By:	 	 

 
			
	Name:	 	Janet White
	Title:	 	Trustee

  
 [Signature Page
to Stockholders Agreement] 

 
			
	 JANET WHITE 2021

IRREVOCABLE TRUST

 
			
		
	 By:
	 	 

 
			
	 Name:
	 	 Howard Spector

	 Title: 
	 	 Trustee

  
 [Signature Page
to Stockholders Agreement] 

 
			
	C. THOMAS ALLGOOD
		
	 By:
	 	 

  
 [Signature Page
to Stockholders Agreement] 

 
			
	NELSON BLITZ
		
	 By:
	 	 

  
 [Signature Page
to Stockholders Agreement] 

 
			
	OTHER HOLDERS:
	
	STANLEY EVRARD
		
	 By:
	 	 

  
 [Signature Page
to Stockholders Agreement] 

 
			
	MATHEW BRALEY
		
	By:	 	 

  
 [Signature Page to
Stockholders Agreement] 

 
			
	JASON BAKER
		
	By:	 	 

  
 [Signature Page to
Stockholders Agreement] 

 
			
	KEVIN MOON
		
	By:	 	 

  
 [Signature Page to
Stockholders Agreement] 

 
			
	RENEE CHENUE
		
	By:	 	 

  
 [Signature Page to
Stockholders Agreement] 

 EXHIBIT A 

DEFINITIONS 
 Capitalized
terms used in this Agreement have the meanings set forth below. 
 “Affiliate” of any Person means any other Person
controlled by, controlling or under common control with such Person. For the purposes of this definition, “control” (including, with its correlative meanings, the terms “controlled by” and “under common control with”),
as used with respect to any Person, shall mean the possession, directly or indirectly, of the power to direct, or cause the direction of the management and policies of such Person, whether through the ownership of securities, by contract or
otherwise. 
 “Agreement” has the meaning set forth in the recitals. 

“Automatic Shelf Registration Statement” has the meaning set forth in Section 1(a). 

“Business Day” means a day that is not a Saturday or Sunday or a day on which banks in New York City are closed. 

“Common Equity” means the Company’s common stock, par value $0.001 per share. 

“Company” has the meaning set forth in the preamble and shall include its successor(s). 

“Company Indemnitee” has the meaning set forth in Section 6. 

“Demand Registrations” has the meaning set forth in Section 1(a). 

“End of Suspension Notice” has the meaning set forth in Section 1(f)(ii). 

“Exchange Act” means the Securities Exchange Act of 1934, as amended from time to time, or any successor federal law then in
force, together with all rules and regulations promulgated thereunder. 
 “Excluded Registration” means any registration
(i) pursuant to a Demand Registration (which is addressed in Section 1(a)), (ii) in connection with registrations on Form S-4 or S-8
promulgated by the SEC (or any successor or similar forms) or (iii) on any form that does not include substantially the same information as would be required to be included in a registration statement covering the sale of Registrable Securities
or that does not permit the registration of Registrable Securities. 
 “FINRA” means the Financial Industry Regulatory
Authority. 
 “Free Writing Prospectus” means a free-writing prospectus, as defined in Rule 405. 

“General Atlantic” has the meaning set forth in the preamble. 

  
 A-1 

 “Holdback Period” has the meaning set forth in
Section 3(a). 
 “Holder” means a holder of Registrable Securities who is a party to this
Agreement (including by way of Joinder). 
 “Indemnified Parties” has the meaning set forth in
Section 6(a). 
 “Investor” and “Investors” has the meaning set forth in the
recitals. 
 “Investor Registrable Securities” means (i) any Common Equity held (directly or indirectly) by an
Investor or any of its Affiliates, and (ii) any equity securities of the Company or any Subsidiary issued or issuable with respect to the securities referred to in clauses (i) above by way of dividend, distribution, split or combination of
securities, conversion, or any recapitalization, merger, consolidation or other reorganization. 
 “Joinder” has the
meaning set forth in Section 9(a).  
 “Long-Form Registrations” has the meaning set forth in
Section 1(a). 
 “Losses” has the meaning set forth in Section 6(c).

 “Majority Investors” means the Investors that are holders of a majority of all Investor Registrable Securities, measured
by reference to shares of Common Equity beneficially owned or issuable upon conversion of an Investor Registrable Security. 

“Majority Participating Investors” means the Participating Investor or Participating Investors who hold a majority of the
Investor Registrable Securities to be included within such Demand Registration, Shelf Offering, Piggyback Registration or Underwritten Block Trade. 

“Other Holders” has the meaning set forth in the recitals. 

“Other Registrable Securities” means (i) any Common Equity held (directly or indirectly) by any Other Holders or
any of their Affiliates, and (ii) any equity securities of the Company or any Subsidiary issued or issuable with respect to the securities referred to in clause (i) above by way of dividend, distribution, split or combination of
securities, or any recapitalization, merger, consolidation, reorganization or certain other corporate transactions. 
 “Other
Securities” has the meaning set forth in Section 3(a). 
 “Participating Investor” or “Participating
Investors” means any Investor(s) participating in the request for a Demand Registration, Shelf Offering, Piggyback Registration or Underwritten Block Trade. 

“Person” means an individual, a partnership, a corporation, a limited liability company, an association, a joint stock
company, a trust, a joint venture, an unincorporated organization and a governmental entity or any department, agency or political subdivision thereof. 

“Piggyback Registrations” has the meaning set forth in Section 2(a). 

  
 A-2 

 “Potential Participant” has the meaning set forth in
Section 1(d). 
 “Public Offering” means any sale or distribution by the Company, one of its
Subsidiaries and/or Holders to the public of Common Equity or other securities convertible into or exchangeable for Common Equity pursuant to an offering registered under the Securities Act. 

“Qualified Independent Underwriter” has the meaning set forth by FINRA in Section 5121(f)(12), or any successor
provision thereto. 
 “Registrable Securities” means Investor Registrable Securities and Other Registrable Securities. As
to any particular Registrable Securities, such securities will cease to be Registrable Securities when they have been (a) sold or distributed pursuant to a Public Offering, (b) sold in compliance with Rule 144 following the consummation of
the Company’s initial Public Offering, (c) distributed to the direct or indirect partners or members of an investor except for a distribution or assignment permitted pursuant to Section 4(e) or
(d) repurchased by the Company or a Subsidiary of the Company. For purposes of this Agreement, a Person will be deemed to be a holder of Registrable Securities, and the Registrable Securities will be deemed to be in existence, whenever such
Person has the right to acquire, directly or indirectly, such Registrable Securities (upon conversion or exercise in connection with a transfer of securities or otherwise, but disregarding any restrictions or limitations upon the exercise of such
right), whether or not such acquisition has actually been effected, and such Person will be entitled to exercise the rights of a holder of Registrable Securities hereunder (it being understood that a holder of Registrable Securities may only request
that Registrable Securities in the form of Common Equity be registered pursuant to this Agreement). Notwithstanding the foregoing, following the consummation of an initial Public Offering, any Registrable Securities held by any Person (other than an
Investor or its Affiliates) that may be sold under Rule 144(b)(1)(i) without limitation under any of the other requirements of Rule 144 will be deemed not to be Registrable Securities. 

“Registration Expenses” has the meaning set forth in Section 5. 

“Rule 144”, “Rule 158”, “Rule 405”, “Rule 415”, “Rule
403B” and “Rule 462” mean, in each case, such rule promulgated under the Securities Act (or any successor provision) by the SEC, as the same will be amended from time to time, or any successor rule then in force. 

“Sale Transaction” has the meaning set forth in Section 3(a). 

“SEC” means the United States Securities and Exchange Commission. 

“Securities” has the meaning set forth in Section 3(a). 

“Securities Act” means the Securities Act of 1933, as amended from time to time, or any successor federal law then in force,
together with all rules and regulations promulgated thereunder. 
 “Shelf Offering” has the meaning set forth in
Section 1(d)(i). 
 “Shelf Offering Notice” has the meaning set forth in
Section 1(d)(i). 

  
 A-3 

 “Shelf Registration” has the meaning set forth in
Section 1(a). 
 “Shelf Registrable Securities” has the meaning set forth in
Section 1(d)(i). 
 “Shelf Registration Statement” has the meaning set forth in
Section 1(d). 
 “Short-Form Registrations” has the meaning set forth in
Section 1(a). 
 “Subsidiary” means, with respect to the Company, any corporation, limited
liability company, partnership, association or other business entity of which (i) if a corporation, a majority of the total voting power of shares of stock entitled (without regard to the occurrence of any contingency) to vote in the election
of directors, managers or trustees thereof is at the time owned or controlled, directly or indirectly, by the Company or one or more of the other Subsidiaries of the Company or a combination thereof, or (ii) if a limited liability company,
partnership, association or other business entity, a majority of the limited liability company, partnership or other similar ownership interest thereof is at the time owned or controlled, directly or indirectly, by the Company or one or more
Subsidiaries of the Company or a combination thereof. For purposes hereof, a Person or Persons will be deemed to have a majority ownership interest in a limited liability company, partnership, association or other business entity if such Person or
Persons will be allocated a majority of limited liability company, partnership, association or other business entity gains or losses or will be or control the managing director or general partner of such limited liability company, partnership,
association or other business entity. 
 “Summit” has the meaning set forth in the preamble. 

“Suspension Event” has the meaning set forth in Section 1(f)(ii). 

“Suspension Notice” has the meaning set forth in Section 1(f)(ii). 

“Suspension Period” has the meaning set forth in Section 1(f)(i). 

“Underwritten Block Trade” has the meaning set forth in Section 1(c)(ii). 

“Violation” has the meaning set forth in Section 6(a). 

“WKSI” means a “well-known seasoned issuer” as defined under Rule 405. 

  
 A-4 

 EXHIBIT B 

The undersigned is executing and delivering this Joinder pursuant to the Registration Rights Agreement dated as of ________, 2021 (as amended,
modified and waived from time to time, the “Registration Agreement”), among EngageSmart, Inc., a Delaware corporation (the “Company”), and the other persons named as parties therein (including pursuant to
other Joinders). Capitalized terms used herein have the meaning set forth in the Registration Agreement. 
 By executing and delivering this
Joinder to the Company, the undersigned hereby agrees to become a party to, to be bound by, and to comply with the provisions of, the Registration Agreement as a Holder in the same manner as if the undersigned were an original signatory to the
Registration Agreement, and the undersigned will be deemed for all purposes to be a Holder, an [Investor // Other Holder thereunder] and the undersigned’s ____ Common Equity will be deemed for all purposes to be [Investor
// Other] Registrable Securities under the Registration Agreement. 
 Accordingly, the undersigned has executed and delivered this
Joinder as of the ___ day of ____________, 20___. 
  

			
	 Signature

 

	Print Name
		
	 Address:
	 	 
	 
	 

 Agreed and Accepted as of 

________________, 20___: 
 EngageSmart, Inc. 

________________________ 
 Its: ________________________

  
 B-1EX-4.2

 Exhibit 4.2 

STOCKHOLDERS AGREEMENT 

This STOCKHOLDERS AGREEMENT (this “Agreement”) is made and entered into as of _________, 2021, by and among EngageSmart, Inc.
(formerly EngageSmart, LLC), a Delaware corporation (the “Company”), General Atlantic (IC), L.P., a Delaware limited partnership (together with its affiliated investment entities, the “GA Stockholder”), Summit
Partners Growth Equity Fund VIII-A, L.P., a Delaware limited partnership, Summit Partners Growth Equity Fund VIII-B, L.P., a Delaware limited partnership, Summit
Partners Entrepreneur Advisors Fund I, L.P., a Delaware limited partnership, Summit Investors I, LLC, a Delaware limited liability company, and Summit Investors I (UK), L.P., a Cayman Islands exempted limited partnership (collectively, the
“Summit Stockholder” and, together with the GA Stockholder, the “Lead Stockholders”) and Robert Bennett, an individual (“Bennett” and, together with the Lead Stockholders, the
‘Stockholders’ and individually, a “Stockholder”). 
 RECITALS 

WHEREAS, as of the date hereof, the Lead Stockholders collectively hold a majority of the outstanding capital stock of the Company; 

WHEREAS, in connection with, and effective upon, the date of completion of the initial public offering of the Company (the “Effective
Date”), the Company and the Stockholders wish to set forth certain understandings between such parties, including with respect to certain governance matters. 

NOW, THEREFORE, in consideration of the mutual covenants and agreements contained herein and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the Company and the Stockholders agree as follows: 
 AGREEMENT 

1. Defined Terms. In addition to the terms defined elsewhere herein, the following terms have the following meaning when used herein with initial
capital letters: 
 “Affiliate” of any Person shall mean any other Person controlled by, controlling or under common control
with such first Person; where “control” (including, with its correlative meanings, “controlling,” “controlled by” and “under common control with”) means possession, directly or indirectly,
of the power to direct or cause the direction of management or policies (whether through ownership of securities, by contract or otherwise). 

“Beneficially Own” shall mean that a specified person has or shares the right, directly or indirectly, through any contract,
arrangement, understanding, relationship or otherwise, to vote shares of capital stock of the Company. 
 “Board” means the
board of directors of the Company. 
 “Common Stock” means common stock of the Company, par value $0.001 per share. 

“Director” means any member of the Board. 

 “Indebtedness” means (a) all indebtedness of the Company and
any of its Subsidiaries for borrowed money, (b) all obligations of the Company and any of its Subsidiaries evidenced by bonds, debentures, notes, loan agreements or other similar instruments, (c) the amount of all drafts drawn under any
and all letters of credit issued for the account of the Company or any of its Subsidiaries (but only to the extent of any unreimbursed drawings under any letter of credit), (d) all Indebtedness of any other Person secured by any Lien on
any property owned by the Company or any of its Subsidiaries, whether or not such Indebtedness has been assumed by the Company or any of its Subsidiaries, (e) all obligations of the Company and any of its Subsidiaries to pay the
deferred purchase price of property or services (including any earnout obligation), except trade accounts payable arising and paid in the ordinary course of business, (f) the capitalized amount of all capital leases of the Company and any of
its Subsidiaries, (g) any liability of the Company or any of its Subsidiaries under any interest rate, currency or commodity swap agreement, cap agreement or collar agreement, and any other agreement or arrangement designed to protect the
Company and any of its Subsidiaries against fluctuations in interest rates, currency exchange rates or commodity prices, (h) all guarantees with respect to any Indebtedness of any other Person of the type described in clauses (a) through
(g) of this definition. 
 “Lien” means any encumbrance, restriction, claim, mortgage, pledge, charge, assignment,
hypothecation, security interest, title retention, banker’s lien, privilege or priority of any kind having the effect of security. 

“Person” means any individual, corporation, limited liability company, partnership, trust, joint stock company, business
trust, unincorporated association, joint venture, governmental authority or other entity or organization, including a government or any subdivision or agency thereof. 

“Subsidiary” means with respect to any Person, any corporation, limited liability company, partnership, association, trust or
other form of legal entity, of which (a) such first Person directly or indirectly owns or controls at least a majority of the securities or other interests having by their terms voting power to elect a majority of the board of directors or
others performing similar functions, or (b) such first Person is a general partner or managing member (excluding partnerships in which such Person or any Subsidiary thereof does not have a majority of the voting interests in such partnership).

  

	2.	 Board of Directors. 

(a) Subject to the other provisions of this Section 2, as of the Effective Date, the number of Directors constituting
the full Board shall initially be fixed at eight (8), who shall be divided into three (3) classes of Directors in accordance with the terms of the Company’s Certificate of Incorporation. As of the Effective Date, the eight
(8) directors shall be divided into three (3) classes as follows: 
 (i) the initial Class I Directors shall include Preston
McKenzie, Ashley Glover and Debbie Dunnam; 

  
 2 

 (ii) the initial Class II Directors shall include Raph Osnoss, David Mangum and Matthew
Hamilton; and 
 (iii) the initial Class III Directors shall include Paul Stamas and Robert Bennett. 

(b) The initial term of the Class I directors shall expire immediately following the Company’s 2022 annual meeting of stockholders
at which directors are elected. The initial term of the Class II directors shall expire immediately following the Company’s 2023 annual meeting of stockholders at which directors are elected. The initial term of the Class III
directors shall expire immediately following the Company’s 2024 annual meeting at which directors are elected. For the avoidance of doubt, Section 2(a) is applicable solely to the initial composition of the Board,
except that, subject to the Company’s Certificate of Incorporation, a Director shall remain a member of the class of Directors to which he or she was assigned in accordance with Section 2(a) and (ii) the initial
terms of each class of directors shall expire as set forth in this Section 2(b). 
 (c) From the Effective Date,
the GA Stockholder shall have the right, but not the obligation, to nominate to the Board a number of designees (such persons, the “GA Nominees”), one of whom shall be designated as the Chairman of the Board (unless the General
Atlantic Stockholder, in its sole discretion, designates a Director other than a GA Nominee as the Chairman of the Board), equal to at least: (i) five (5) Directors, so long as the GA Stockholder Beneficially Owns shares of Common Stock
representing over 50% of the Common Stock then outstanding, at least two (2) of which such Directors must be “independent directors” under applicable law and stock exchange listing standards, (ii) three (3) Directors, so long as
the GA Stockholder Beneficially Owns shares of Common Stock representing at least 30% but less than or equal to 50% of the Common Stock then outstanding, (iii) two (2) Directors so long as the GA Stockholder Beneficially Owns shares of Common
Stock representing at least 20% but less than 30% of the Common Stock then outstanding and (iv) one (1) Director so long as the GA Stockholder Beneficially Owns shares of Common Stock representing at least 10%. The initial GA Nominees shall be
Paul Stamas, Raph Osnoss, Preston McKenzie, David Mangum and Ashley Glover. The initial Chairman of the Board shall be Paul Stamas. At the GA Stockholder’s request, each class of Directors shall include, to the extent practicable, at least one
Nominee designated by the GA Stockholder. 
 (d) From the Effective Date, the Summit Stockholder shall have the right, but not the
obligation, to nominate to the Board one (1) Director (such person, the “Summit Nominee”) so long as the Summit Stockholder Beneficially Owns shares of Common Stock representing at least 10% of the Common Stock then
outstanding. The initial Summit Nominee shall be Matthew Hamilton. 
 (e) Bennett shall have the right to be nominated to the Board (in such
capacity, the “Founder Nominee” and, together with the GA Nominees and the Summit Nominee, the “Nominees”) so long as Company is a “controlled company” under the securities exchange on which the Common
Stock is listed (“Controlled Company Eligible”). 

  
 3 

 (f) In the event that either the GA Stockholder or the Summit Stockholder has nominated less
than the total number of designees that such Lead Stockholder shall be entitled to nominate pursuant to Section 2(c) and Section 2(d), as applicable, such Lead Stockholder shall have the right, at
any time, to nominate such additional designees to which it is entitled, in which case, the Company and the Directors shall take all necessary corporation action, to the fullest extent permitted by applicable law (including with respect to fiduciary
duties under Delaware law), to (x) enable such Lead Stockholder to nominate and effect the election or appointment of such additional individuals, whether by increasing the size of the Board, or otherwise and (y) to designate such
additional individuals nominated by such Lead Stockholder to fill such newly created vacancies or to fill any other existing vacancies. 

(g) The Company shall pay all reasonable and documented
out-of-pocket expenses incurred by any Nominee in connection with the performance of his or her duties as a Director and in connection with his or her attendance at any
meeting of the Board. 
 (h) No reduction in the number of shares of Common Stock that each Lead Stockholder Beneficially Owns shall shorten
the term of any incumbent Director. 
 (i) In the event that any GA Nominee or Summit Nominee shall cease to serve for any reason during a
term, the Lead Stockholder that nominated such Nominee shall be entitled to designate such person’s successor in accordance with this Agreement (regardless of each Lead Stockholder’s Beneficial Ownership of Common Stock at the time of such
vacancy) and the Board shall promptly fill the vacancy with such successor nominee; it being understood that any such designee shall serve the remainder of the term of the Director whom such designee replaces. 

(j) If a GA Nominee or Summit Nominee is not appointed or elected to the Board because of such person’s death, disability,
disqualification, withdrawal as a Nominee or for another reason is unavailable or unable to serve on the Board, the applicable Lead Stockholder shall be entitled to designate promptly another Nominee and the Director position for which the original
Nominee was nominated shall not be filled pending such designation. 
 (k) For so long as the GA Stockholder Beneficially Owns shares of
Common Stock representing (i) at least 50% of the Common Stock then outstanding, the stockholders of the Company shall have the right to remove directors (other than the Summit Director and Bennett) with or without cause upon the vote of
holders that Beneficially Own shares of Common Stock representing over 50% of the Common Stock then outstanding or (ii) less than 50% of the Common Stock then outstanding, stockholders of the Company shall have the right to remove directors
only for cause upon the vote of holders that Beneficially Own shares of Common Stock representing over 66 2/3% of the Common Stock then outstanding. Subject to Sections 2(c) and 2(d), for so long as the GA Stockholder Beneficially Owns
shares of Common Stock representing (i) at least 50% of the Common Stock then outstanding, the stockholders of the Company or the Board shall have the right to designate for election to the Board directors to fill vacancies created by reason of
the permanent disability, death, removal or resignation of its designees to the Board or (ii) less than 50% of the Common Stock then outstanding, the Board shall have the right to fill such vacancies. 

  
 4 

 (l) At such times as the Company is required by applicable law or stock exchange listing
standards to have a majority of the Board comprised of “independent directors” (subject in each case to any applicable phase-in periods), the Nominees shall include a number of persons that qualify
as “independent directors” under applicable law and stock exchange listing standards such that, together with any other “independent directors” then serving on the Board that are not Nominees, the Board is comprised of a majority
of “independent directors”; provided, that at any time that the GA Stockholder shall have any nomination rights under this Section 2, the GA Stockholder shall be entitled to nominate at least one
(1) Nominee who does not qualify as an “independent director”. 
 (m) At any time the Summit Stockholder shall be entitled to
nomination rights under Section 2(d), the Company shall not increase or decrease the number of Directors serving on the Board without the prior written consent of the the Summit Stockholder. 

 

	3.	 Company and Stockholder Obligations. 

(a) The Company agrees that, prior to the date that each Lead Stockholder ceases to Beneficially Own shares of Common Stock representing at
least 5% of the Common Stock then outstanding, (i) each Nominee (other than Bennett if the Company ceases to be Controlled Company Eligible) is included in the Board’s slate of nominees to the stockholders (the “Board’s
Slate”) for each election of Directors; and (ii) each Nominee (other than Bennett if the Company ceases to be Controlled Company Eligible) is included in the proxy statement prepared by management of the Company in connection with
soliciting proxies for every meeting of the stockholders of the Company called with respect to the election of Directors (each, a “Director Election Proxy Statement”), and at every adjournment or postponement thereof, and on every
action or approval by written consent of the stockholders of the Company or the Board with respect to the election of members of the Board. Each Lead Stockholder will promptly report to the Company after such Lead Stockholder ceases to Beneficially
Own shares of Common Stock representing at least 5% of the Common Stock then outstanding, such that the Company is informed of when this obligation terminates; provided, that such obligation of such Lead Stockholder to notify the Company
shall be deemed satisfied if such Lead Stockholder makes a filing under Section 16 of the Securities Exchange Act of 1934 reflecting such change in the Common Stock Beneficially Owned by such Lead Stockholder. The calculation of the number of
Nominees that each Lead Stockholder is entitled to nominate to the Board’s Slate for any election of Directors shall be based on the percentage of the Common Stock then outstanding Beneficially Owned by each Lead Stockholder (“Lead
Stockholder Voting Control”) immediately prior to the mailing to stockholders of the Director Election Proxy Statement relating to such election (or, if earlier, the filing of the definitive Director Election Proxy Statement with the U.S.
Securities and Exchange Commission). Unless a Lead Stockholder notifies the Company otherwise prior to the mailing to stockholders of the Director Election Proxy Statement relating to an election of Directors, the Nominees for such election shall be
presumed to be the same Nominees currently serving on the Board, and no further action shall be required of any Lead Stockholder for the Board to include such Nominees on the Board’s Slate; provided, that, in the event a Lead Stockholder
is no longer entitled to nominate the full number of Nominees then serving on the Board, such Lead 

  
 5 

 
Stockholder shall provide advance written notice to the Company of which currently serving Nominee(s) shall be excluded from the Board Slate, and of any other changes to the list of Nominees. If
a Lead Stockholder fails to provide such notice prior to the mailing to stockholders of the Director Election Proxy Statement relating to such election (or, if earlier, the filing of the definitive Director Election Proxy Statement with the U.S.
Securities and Exchange Commission), a majority of the independent directors then serving on the Board shall determine which of the Nominees of such Lead Stockholder then serving on the Board will be included in the Board’s Slate. 

(b) At any time that a Stockholder shall have any nomination rights under Section 2, the Company shall not take any
action, including making or recommending any amendment to Company’s Certificate of Incorporation or Bylaws (each as may be further amended, supplemented or waived in accordance with its terms) that could reasonably be expected to adversely
affect a Stockholder’s rights under this Agreement, in each case without the prior written consent of the adversely affected Stockholder. 
  

	4.	 Committees. 

(a) For so long as (i) the GA Stockholder has the right to nominate any GA Nominees to the Board pursuant to
Section 2(a) hereof, the GA Stockholder shall have the right to designate one member of each committee of the Board and (ii) the Summit Stockholder has the right to nominate the Summit Nominee to the Board pursuant to
Section 2(a) hereof, the Summit Stockholder shall have the right to designate one member to the compensation committee of the Board; provided, that any such designee shall be a Director and shall be eligible to serve
on the applicable committee under applicable law or stock exchange listing standards, including any applicable independence requirements (subject in each case to any applicable exceptions, including those for newly public companies and any
applicable phase-in periods). Any additional committee members shall be determined by the Board. The GA Nominees and Summit Nominee designated to serve on a Board committee shall have the right to remain on
such committee until the next election of Directors, regardless of the level of Lead Stockholder Voting Control following such designation. Unless a Lead Stockholder notifies the Company otherwise prior to the time the Board takes action to change
the composition of a Board committee, and to the extent the applicable Lead Stockholder has the requisite Lead Stockholder Voting Control for such Lead Stockholder to nominate a Board committee member at the time the Board takes action to change the
composition of any such Board committee, any Nominee currently designated by the applicable Lead Stockholder to serve on a committee shall be presumed to be re-designated for such committee. 

(b) From and after the Effective Date until such time as the GA Stockholder ceases to Beneficially Own Common Stock representing at
least 15% of the Common Stock then outstanding, the Company shall take all necessary action to cause the chairperson of each of the nominating and governance committee, the compensation committee and the audit committee of the Board to be a person
selected by the GA Stockholder from among the Directors then in office from time to time; provided, that, any such selections will be in compliance with applicable law and stock exchange listing standards. The initial chairperson of the
(i) nominating and governance committee shall be Paul Stamas, (ii) compensation committee shall be Preston McKenzie and (iii) audit committee shall be David Mangum. 

  
 6 

 5. Major Actions. In addition to any voting requirements contained in the Certificate of
Incorporation or the Bylaws (or similar governing documents) of the Company or any of its Subsidiaries, the following actions shall not be taken by the Company or any of its Subsidiaries, directly or indirectly (whether by merger, consolidation,
reorganization or otherwise), including any proposal by the Board to put to the vote of the stockholders of the Company with respect thereto, without the prior written consent of the GA Stockholder for so long as the GA Stockholder Beneficially Owns
shares of Common Stock representing at least 25% (or as otherwise specified below) of the Common Stock then outstanding: 
 (a) any
acquisition or disposition where aggregate consideration is greater than $150,000,000 in a single transaction or series of related transactions; 

(b) any transaction in which any Person or group acquires more than 50% of the then outstanding capital stock of the Company or the power to
elect a majority of the members of the Board; 
 (c) any incurrence or refinancing of Indebtedness of the Company and its Subsidiaries to
the extent such incurrence or refinancing would result in the Company and its Subsidiaries having Indebtedness in excess of $250,000,000 in the aggregate; 

(d) hiring or termination of the chief executive officer of the Company; 

(e) for so long as the GA Stockholder Beneficially Owns shares of Common Stock representing at least 10% of the Common Stock then outstanding,
any increase or decrease in the size of the Board; 
 (f) any reorganization, recapitalization, voluntary bankruptcy, liquidation,
dissolution or winding-up; 
 (g) any redemption, repurchase or other acquisition by the Company of
its equity securities or any declaration thereof, other than (i) the redemption, repurchase or other acquisition by the Company of any equity securities of any director, officer, independent contractor or employee in connection with the
termination of the employment or services of such director, officer, independent contractor or employee as contemplated by the applicable equity compensation plan or award agreement with respect to such equity securities, (ii) pursuant to an
offer made to all stockholders of the Company pro rata with respect to such equity securities (regardless of whether any or all of such stockholders elect to participate in such redemption, repurchase or other acquisition) or
(iii) pursuant to an open market plan approved by the Board; 
 (h) any payment or declaration of any dividend or distribution on any
equity securities of the Company or any of its non-wholly-owned Subsidiaries or entering into a recapitalization transaction the primary purpose of which is to pay a dividend or distribution; 

(i) any amendment, alteration or repeal of any provision of the governing documents of the Company in a manner that adversely affects the
powers, preferences or rights of the GA Stockholder (including, for the avoidance of doubt, the advance waiver of corporate opportunities); or 

  
 7 

 (j) any adoption, approval or issuance of any “poison pill,” stockholder or
similar rights plan by the Company or its Subsidiaries or any amendment, restatement, modification or waiver of such plan after the adoption thereof has been approved by the GA Stockholder in accordance with this Section 5.

 6. Information Rights. For so long as the GA Stockholder Beneficially Owns shares of Common Stock representing at least 10% of the Common Stock
then outstanding, the Company shall provide the GA Stockholder or its authorized representatives with (i) (x) reasonable access to visit and inspect any of the properties of the Company or any of its Subsidiaries, including its and their books
of account, monthly management reports, operating and capital expenditure budgets, periodic information packages relating to the operations and cash flows of the Company and other records and (y) the right to discuss the Company’s or its
Subsidiaries’ affairs, finances and accounts with its and their officers, during normal business hours following reasonable notice, and (ii) for so long as the Company is not a public reporting company, (x) an unaudited consolidated
balance sheet of the Company as of the end of each completed fiscal quarter in each year following the date hereof and (y) an audited annual consolidated balance sheet of the Company as of the end of the fiscal year in each year following the
date hereof and the related audited consolidated statements of income, changes in stockholders’ equity and cash flow for the fiscal years then ended, including the notes thereto; provided, however, that the Company shall not be
obligated pursuant to the foregoing clauses (i) and (ii) to provide access to any information that it reasonably and in good faith considers to be a trade secret or confidential information (unless covered by an enforceable confidentiality
agreement, in a form acceptable to the Company) or the disclosure of which would adversely affect the attorney-client privilege between the Company and its counsel. For so long as the GA Stockholder Beneficially Owns shares of Common Stock
representing at least 10% of the Common Stock then outstanding, the Company shall also provide the GA Stockholder or its authorized representatives with the right to reasonably request information. 

7. Confidential Information. The Company recognizes that Nominees (a) will from time to time receive
non-public information concerning the Company, and (b) may share such information with other individuals associated with the Lead Stockholder that designated such Nominee. The Company hereby irrevocably
consents to such sharing, subject to the terms of this Section 7. Each Lead Stockholder agrees that it will keep confidential and not disclose or divulge to any third party, or use for any purpose, other than to monitor its
investment in the Company and its Subsidiaries, any confidential information regarding the Company it receives from the Company or a Nominee, unless such information (x) is known or becomes known to the public in general, (y) is or has
been independently developed or conceived by such Lead Stockholder without use of the Company’s confidential information or (z) is or has been made known or disclosed to such Lead Stockholder by a third party without a breach of any
obligation of confidentiality such third party may have; provided, however, that a Lead Stockholder may disclose confidential information (i) to its Affiliates (other than portfolio companies), (ii) to each of its and its
Affiliates’ (other than portfolio companies) attorneys, accountants, consultants, advisors and other professionals to the extent necessary to obtain their services in connection with evaluating the information, or (iii) as may be required
by law or legal, judicial or regulatory process or requested by any regulatory or self-regulatory authority or examiner, provided that such Lead Stockholder takes reasonable steps to minimize the extent of any required disclosure described in this
clause (iii); provided, further, that each Lead Stockholder shall be responsible for compliance with this Section 7 by its Affiliates and advisors described in the foregoing clauses (i) and (ii). 

  
 8 

	8.	 Indemnification. 

(a) The Company agrees to indemnify and hold harmless each Stockholder, its respective directors, officers, partners, members, managers,
Affiliates and controlling persons (each, an “Stockholder Indemnitee”) from and against any and all liability, including, without limitation, all obligations, costs, fines, claims, actions, injuries, demands, suits, judgments,
proceedings, investigations, arbitrations (including stockholder claims, actions, injuries, demands, suits, judgments, proceedings, investigations or arbitrations) and reasonable and documented expenses, including reasonable accountant’s and
reasonable attorney’s fees and expenses (together the “Losses”), incurred by such Stockholder Indemnitee before or after the date of this Agreement to the extent arising out of, resulting from, or relating to (i) such
Stockholder Indemnitee’s purchase and/or ownership of any Common Stock or (ii) any litigation to which any Stockholder Indemnitee is made a party in its capacity as a stockholder or owner of securities (or as a director, officer, partner,
member, manager, Affiliate or controlling person of any Lead Stockholder) of the Company (including any predecessor thereof); provided, that the foregoing indemnification rights in this Section 8(a) shall not be
available to the extent that (a) any such Losses are incurred as a result of such Stockholder Indemnitee’s willful misconduct or gross negligence; (b) any such Losses are incurred as a result of
non-compliance by such Stockholder Indemnitee with any laws or regulations applicable to it; or (c) subject to the rights of contribution provided for below, to the extent indemnification for any Losses
would violate any applicable law or public policy. For purposes of this Section 8(a), none of the circumstances described in the limitations contained in the proviso in the immediately preceding sentence shall be deemed to
apply absent a final non-appealable judgment of a court of competent jurisdiction to such effect, in which case to the extent any such limitation is so determined to apply to any Stockholder Indemnitee as to
any previously advanced indemnity payments made by the Company under this Section 8(a), then such payments shall be promptly repaid by such Stockholder Indemnitee to the Company. No reduction in the number of shares of
Common Stock that each Lead Stockholder Beneficially Owns shall affect the coverage provided herein. The rights of any Stockholder Indemnitee to indemnification hereunder will be in addition to any other rights any such party may have under any
other agreement or instrument to which such Stockholder Indemnitee is or becomes a party or is or otherwise becomes a beneficiary or under law or regulation. In the event of any payment of indemnification pursuant to this
Section 8(a), to the extent that any Stockholder Indemnitee is indemnified for Losses, except as set forth in Section 7(d), the Company will be subrogated to the extent of such payment to all of
the related rights of recovery of the Stockholder Indemnitee to which such payment is made against all other Persons. Such Stockholder Indemnitee shall execute all papers reasonably required to evidence such rights. The Company will be entitled at
its election to participate in the defense of any third party claim upon which indemnification is due pursuant to this Section 8(a) or to assume the defense thereof, with counsel reasonably satisfactory to such Stockholder
Indemnitee unless, in the reasonable judgment of the Stockholder Indemnitee, a conflict of interest between the Company and such Stockholder Indemnitee may exist, in which case such Stockholder Indemnitee shall have the right to assume its own
defense and the Company shall be liable for all reasonable expenses therefor. Except as set forth above, should the Company assume such defense all further defense costs of the Stockholder Indemnitee in respect of such third party claim shall be for
the sole account of such party and not subject to indemnification hereunder. The Company 

  
 9 

 
will not without the prior written consent of the Stockholder Indemnitee (which consent shall not be unreasonably withheld) effect any settlement of any threatened or pending third party claim in
which such Stockholder Indemnitee is or could have been a party and be entitled to indemnification hereunder unless such settlement solely involves the payment of money by the Company and includes an unconditional release of such Stockholder
Indemnitee from all liability and claims that are the subject matter of such claim. If the indemnification provided for above is unavailable in respect of any Losses, then the Company, in lieu of indemnifying an Stockholder Indemnitee, shall, if and
to the extent permitted by law, contribute to the amount paid or payable by such Stockholder Indemnitee in such proportion as is appropriate to reflect the relative fault of the Company and such Stockholder Indemnitee in connection with the actions
which resulted in such Losses, as well as any other equitable considerations. 
 (b) The Company agrees to pay or reimburse (i) the
Lead Stockholders for all reasonable and documented costs and expenses (including reasonable and documented attorneys’ fees, charges, disbursement and expenses) incurred in connection with any amendment, supplement, modification or waiver of,
or to, any of the terms or provisions of this Agreement or any related agreements and (ii) each Lead Stockholder for all reasonable and documented costs and expenses of such Lead Stockholder (including reasonable and documented attorneys’
fees, charges, disbursement and expenses) incurred in connection with (1) the consent to any departure by the Company or any of its Subsidiaries from the terms of any provision of this Agreement or any related agreements and (2) the
enforcement or exercise by such Lead Stockholder of any right granted to it or provided for hereunder. 
 (c) The Company and its
Subsidiaries shall obtain customary director and officer indemnity insurance on commercially reasonable terms which insurance shall cover each member of the Board and the members of each board of directors of each of the Company’s Subsidiaries.
The Company and its Subsidiaries shall enter into director indemnification agreements substantially in the form attached as Exhibit A hereto, with each of the Nominees. 

(d) The Company hereby acknowledges that the Stockholder Indemnitee may have certain rights to advancement and/or indemnification by
certain Affiliates of the GA Stockholder or certain Affiliates of the Summit Stockholder (collectively, the “Fund Indemnitors”). In all events, (i) the Company hereby agrees that it is the indemnitor of
first resort (i.e., its obligation to a Stockholder Indemnitee to provide advancement and/or indemnification to such Stockholder Indemnitee are primary and any obligation of the Fund Indemnitors (including any Affiliate
thereof other than the Company) to provide advancement or indemnification hereunder or under any other indemnification agreement (whether pursuant to contract, by-laws or charter), or any obligation of
any insurer of the Fund Indemnitors to provide insurance coverage, for the same expenses, liabilities, judgments, penalties, fines and amounts paid in settlement (including all interest, assessments and other charges paid or payable in connection
with or in respect of such expenses, liabilities, judgments, penalties, fines and amounts paid in settlement) incurred by such Stockholder Indemnitee are secondary and it irrevocably waives any claims against the Fund Indemnitors for contribution,
subrogation, reimbursement or any other recovery of any kind for which the Company is entitled pursuant to this Agreement and the Company’s by-laws or charter and (ii) if any Fund Indemnitor (or any
Affiliate thereof, other than the Company) pays or causes to be paid, for any reason, any amounts otherwise indemnifiable hereunder or under any other indemnification agreement (whether pursuant to contract,
by-laws or charter) with such 

  
 10 

 
Stockholder Indemnitee, then (x) such Fund Indemnitor (or such Affiliate, as the case may be) shall be fully subrogated to all rights of such Stockholder Indemnitee with respect to such
payment and (y) the Company shall fully indemnify, reimburse and hold harmless such Fund Indemnitor (or such other Affiliate, as the case may be) for all such payments actually made by such Fund Indemnitor (or such other Affiliate, as the
case may be). 
 9. Amendment and Waiver. Any provision of this Agreement may be amended or waived if, but only if, such amendment or waiver is in
writing and is signed, in the case of an amendment, by the Company and each Lead Stockholder that Beneficially Owns at least 5% of the Common Stock then outstanding, or in the case of a waiver, by the party against whom the waiver is to be
effective; provided, that any amendments or waivers that adversely affect Bennett in a manner disproportionate to the Lead Stockholders shall require the written consent of Bennett. No failure or delay by any party in exercising any right,
power or privilege hereunder shall operate as a waiver thereof nor shall any single or partial exercise thereof preclude any other or further exercise thereof or the exercise of any other right, power or privilege. The rights and remedies herein
provided shall be cumulative and not exclusive of any rights or remedies provided by law. The Lead Stockholders shall not be obligated to nominate all (or any) of the Nominees they are entitled to nominate pursuant to this Agreement for any election
of Directors but the failure to do so shall not constitute a waiver of rights hereunder with respect to future elections. The rights and remedies herein provided shall be cumulative and not exclusive of any rights or remedies provided by law. 

10. Benefit of Parties. This Agreement shall be binding upon and shall inure to the benefit of the parties hereto and their respective permitted
successors and assigns. Notwithstanding the foregoing, the Company may not assign any of its rights or obligations hereunder without the prior written consent of each Lead Stockholder that Beneficially Own shares of Common Stock representing at
least 5% of the Common Stock then outstanding. Except as otherwise expressly provided in Section 11, nothing herein contained shall confer or is intended to confer on any third party or entity that is not a party to this
Agreement any rights under this Agreement. 
 11. Assignment. Upon written notice to the Company, each Lead Stockholder may assign to any Affiliate
(other than a portfolio company) all of its rights hereunder and, following such assignment, such assignee shall be deemed to be a “Lead Stockholder” for all purposes hereunder. 

12. Headings. Headings are for ease of reference only and shall not form a part of this Agreement. 

13. Governing Law. This Agreement shall be construed in accordance with and governed by the law of the State of Delaware without giving effect to the
principles of conflicts of laws thereof. 
 14. Jurisdiction. Any suit, action or proceeding seeking to enforce any provision of, or based on any
matter arising out of or in connection with, this Agreement may be brought against any of the parties in any federal court located in the State of Delaware or any Delaware state court, and each of the parties hereby consents to the exclusive
jurisdiction of such court (and of the appropriate appellate courts) in any such suit, action or proceeding and waives any objection to venue laid therein. Process in any such suit, action or proceeding may be served on any party anywhere in the
world, whether within or without the jurisdiction of any such court. Without limiting the foregoing, each of the parties agrees that service of process upon such party at the address referred to in Section 21, together with
written notice of such service to such party, shall be deemed effective service of process upon such party. 

  
 11 

 15. WAIVER OF JURY TRIAL. EACH OF THE PARTIES HERETO HEREBY IRREVOCABLY WAIVES ANY AND ALL RIGHT TO
TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUT OF OR IN CONNECTION WITH THIS AGREEMENT. 
 16. Entire Agreement. This Agreement constitutes the
entire agreement among the parties with respect to the subject matter hereof and supersedes all prior agreements, understandings and negotiations, both written and oral among the parties with respect to the subject matter hereof. 

17. Termination. This Agreement shall terminate upon the earliest to occur of any one of the following events: (a) (i) with respect to the GA
Stockholder only, at such time as the GA Stockholder no longer Beneficially Owns shares of Common Stock representing at least 10% of the Common Stock then outstanding and (ii) with respect to the Summit Stockholder only, at such time as the
Summit Stockholder no longer Beneficially Owns shares of Common Stock representing at least 10% of the Common Stock then outstanding and (b) the unanimous written consent of the parties hereto. Notwithstanding the foregoing, Sections 8
through 25 shall survive any termination of this Agreement. 
 18. Severability. If any provision of this Agreement or the application thereof
to any person or circumstance shall be invalid or unenforceable to any extent, the remainder of this Agreement and the application of such provisions to other persons or circumstances shall not be affected thereby and shall be enforced to the
greatest extent permitted by law. 
 19. Further Assurances. Each of the parties hereto shall execute and deliver such further instruments and do
such further acts and things as may be required to carry out the intent and purpose of this Agreement. 
 20. Specific Performance. Each of the
parties hereto agree that irreparable damage would occur if any provision of this Agreement were not performed in accordance with the terms hereof and that the parties shall be entitled to an injunction or injunctions to prevent breaches of this
Agreement or to enforce specifically the performance of the terms and provisions hereof in any federal or state court located in the State of Delaware, in addition to any other remedy to which they are entitled at law or in equity. 

21. Notices. All notices, requests and other communications to any party shall be in writing (including email or similar writing) and shall be given:

 If to the Company: 

EngageSmart, Inc. 
 c/o Charles
Kallenbach 
 30 Braintree Hill, Office Park, Ste 101 

Braintree, MA 02184 
 Attention:
Charles Kallenbach 
 Email: ckallenbach@engagesmart.com 

  
 12 

 With a copy to (which shall not constitute notice): 

Latham & Watkins LLP 

1271 Avenue of the Americas 
 New
York, NY 10020 
 Attention: Ian D. Schuman, Stelios G. Saffos, Jonathan Solomon and Brittany Ruiz     

Email: Ian.Schuman@lw.com; Stelios.Saffos@lw.com; Jonathan.Solomon@lw.com and Brittany.Ruiz@lw.com 

If to the GA Stockholder or any of its Nominees: 

c/o General Atlantic Service Company, L.P. 

55 East 52nd Street, 33rd Floor 

New York, NY 10055 
 Attention:
Chris Lanning 
 Email: clanning@generalatlantic.com 

With a copy to (which shall not constitute notice): 

Paul, Weiss, Rifkind, Wharton & Garrison LLP 

1285 Avenue of the Americas 
 New
York, NY 10019-6064 
 Attention: Matthew Abbott; Ellen Ching 

Email: mabbott@paulweiss.com; eching@paulweiss.com 

If to the Summit Stockholder or any of its Nominees: 

c/o Summit Partners, L.P. 
 222
Berkeley St., 18th Floor 
 Boston, MA 02116 

Attention: Christopher J. Dean; Matthew G. Hamilton 

Email: cdean@summitpartners.com; mhamilton@summitpartners.com 

With a copy to (which shall not constitute notice): 

Kirkland & Ellis LLP 

300 North LaSalle St. 
 Chicago,
IL 60654 
 Attention: Brian C. Van Klompenberg, P.C.; Michael P. Keeley 

Email: brian.vanklompenberg@kirkland.com; michael.keeley@kirkland.com 

or to such other address or email address as such party may hereafter specify for the purpose by notice to the other parties. Each such notice, request or
other communication shall be effective when delivered at the address specified in this Section 21 during regular business hours. 

  
 13 

 22. Enforcement. Each of the parties hereto covenants and agrees that the disinterested members of
the Board have the right to enforce, waive or take any other action with respect to this Agreement on behalf of the Company. 
 23. Interpretation.
Each of the parties hereto acknowledges that each party has been represented by legal counsel in connection with this Agreement. Accordingly, any rule of law or any legal decision that would require interpretation of any claimed ambiguities in this
Agreement against the drafting party has no application and is expressly waived. 
 24. Reporting. Each of the Stockholders acknowledge and agree
that nothing in this Agreement shall be deemed to create a group among such Stockholders and the parties hereto shall not take a reporting position that is inconsistent with the foregoing without the prior written consent of the other Stockholders.

 25. Counterparts; Effectiveness. This Agreement may be signed in any number of counterparts, each of which shall be deemed an original. This
Agreement shall become effective when each party shall have received a counterpart hereof signed by each of the other parties. An executed copy or counterpart hereof delivered by facsimile shall be deemed an original instrument. 

[signature page follows] 

  
 14 

 IN WITNESS WHEREOF, the parties hereto have executed this Stockholders Agreement as of the
date first set forth above. 
  

			
	ENGAGESMART, INC.

 
			
		
	By:	 	 
		 	Name:
		 	Title:

 [Signature Page to Stockholders Agreement] 

 
			
	GENERAL ATLANTIC (IC), L.P.
	
	By: General Atlantic (SPV) GP, LLC, its general partner
	
	By: General Atlantic, L.P., its sole member

 
			
		
	By:	 	 

 
			
	Name:	 	
	Title:	 	

 [Signature Page to Stockholders Agreement] 

 
			
	 SUMMIT PARTNERS GROWTH EQUITY

FUND VIII-A, L.P.

	
	 By: Summit Partners GE VIII, L.P.

	 Its: General Partner

	
	 By: Summit Partners GE VIII, LLC

Its: General Partner

 
			
		
	By:	 	 

 
			
	Name:	 	
	Title:	 	

  

			
	 SUMMIT PARTNERS GROWTH EQUITY

FUND VIII-B, L.P.

	
	 By: Summit Partners GE VIII, L.P.

Its: General Partner

	
	 By: Summit Partners GE VIII, LLC

Its: General Partner

 
			
		
	By:	 	 

 
			
	Name:	 	
	Title:	 	

  

			
	 SUMMIT PARTNERS ENTREPRENEUR

ADVISORS FUND L.P.

	
	 By: Summit Partners Entrepreneur Advisors GP, LLC

Its: General Partner

	
	 By: Summit Master Company, LLC
 Its:
Sole Member

 
			
		
	By:	 	 

 
			
	Name:	 	
	Title:	 	

 [Signature Page to Stockholders Agreement] 

 
			
	SUMMIT INVESTORS I, LLC
		
	By:	 	Summit Investors Management, LLC

 
			
	Its:	 	Manager

 
			
		
	By:	 	Summit Partners, L.P.

 
			
	Its:	 	Manager

 
			
		
	By:	 	Summit Master Company, LLC

 
			
	Its:	 	General Partner
		
	By:	 	 

 
			
	Name:	 	
	Title:	 	
	
	SUMMIT INVESTORS I (UK), L.P.

 
			
		
	By:	 	Summit Investors Management, LLC
	Its:	 	General Partner
		
	By: 	 	Summit Partners, L.P.
	Its:	 	Manager
		
	By: 	 	Summit Master Company, LLC
	Its:	 	General Partner

 
			
		
	By:	 	 

 
			
	Name:	 	
	Title:	 	

 [Signature Page to Stockholders Agreement] 

 
			
	ROBERT BENNETT

 
			
		
	By:	 	 

 [Signature Page to Stockholders Agreement]

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