<PAGE>
 
                         EXECUTIVE SEVERANCE AGREEMENT
                         -----------------------------


           This EXECUTIVE SEVERANCE AGREEMENT (the "Agreement"), is made as of
November 4, 1996, by and between ADVO, Inc. (the "Company") and Gary M. Mulloy
(the "Executive").

                                   RECITALS:
                                   -------- 

      A.   The Executive is an executive of the Company and has made and is
expected to continue to make major contributions to the short- and long-term
profitability, growth, and financial strength of the Company;

      B.   The Company recognizes that the possibility of a Change of Control
(as hereafter defined) exists;

      C.   The Company desires to assure itself of both present and future
continuity of its management and desires to establish certain severance benefits
for key executive officers of the Company, including the Executive, applicable
in the event of a Change of Control; and

      D.   The Company wishes to aid in assuring that such executives are not
practically disabled from discharging their duties in respect of a proposed or
actual transaction involving a Change of Control.

      NOW, THEREFORE, the Company and the Executive agree as follows:

1.    Certain Defined Terms:  In addition to terms defined elsewhere herein, the
      ---------------------  
following terms have the following meanings when used in this Agreement with
initial capital letters:

      (a)  "Affiliate" means (i) each entity in which the Company, alone or
together with one or more other Affiliates of the Company, owns not less than
80% of the then outstanding voting securities or, for any entity that is not a
corporation, at least 80% of the then-outstanding capital interests of such
entity and (ii) any additional entity which is deemed by action of the Board to
be an Affiliate for the purposes of this Agreement.

      (b)  "Base Pay" means the Executive's annual aggregate fixed base salary
from the Company at the time in question.
<PAGE>
 
     (c)  "Board" means the Board of Directors of the Company.

     (d)  "Change of Control" means the occurrence during the Term of any of the
following events:

          (i)    The acquisition by any individual, entity or group (within the
meaning of Section 13(d)(3) or 14(d)(2) of the Securities Exchange Act of 1934,
as amended (the "Exchange Act")), other than Warburg (a "Person") of beneficial
ownership (within the meaning of Rule 13d-3 promulgated under the Exchange Act)
of voting securities of the Company where such acquisition causes such Person to
own 30% or more of the combined voting power of the then outstanding voting
securities of the Company entitled to vote generally in the election of
directors (the "Outstanding Company Voting Securities"); provided, however, that
for purposes of this subsection (i), the following acquisitions shall not be
deemed to result in a Change of Control: (A) any acquisition directly from the
Company, (B) any acquisition by the Company, (C) any acquisition by any
employee benefit plan (or related trust) sponsored or maintained by the Company
or any corporation controlled by the Company or (D) any acquisition by any
corporation pursuant to a transaction that complies with clauses (A), (B) and
(C) of subsection (iii) below; and provided, further, that if any Person's
beneficial ownership of the Outstanding Company Voting Securities reaches or
exceeds 30% as a result of a transaction described in clause (A) or (B) above,
and such Person subsequently acquires beneficial ownership of additional voting
securities of the Company, such subsequent acquisition shall be treated as an
acquisition that causes such Person to own 30% or more of the Outstanding
Company Voting Securities; or

          (ii)   Individuals who, as of the date hereof, constitute the Board
(the "Incumbent Board") cease for any reason to constitute at least a majority
of the Board; provided, however, that any individual becoming a director
subsequent to the date hereof whose election, or nomination for election by the
Company's shareholders, was approved by a vote of at least a majority of the
directors then comprising the Incumbent Board shall be considered as though such
individual were a member of the Incumbent Board, but excluding, for this
purpose, any such individual whose initial assumption of office occurs as a
result of an actual or threatened election contest with respect to the election
or removal of directors or other actual or threatened solicitation of proxies or
consents by or on behalf of a Person other than the Board; and provided,
further, than any partner, employee or representative of Warburg proposed by
Warburg to be elected to the Board shall be considered a member of the Incumbent
Board; or

          (iii)  The approval by the shareholders of the Company of a
reorganization, merger or consolidation or sale or other
<PAGE>
 
disposition of all or substantially all of the assets of the Company or the
acquisition of assets of another corporation ("Business Combination") or, if
consummation of such Business Combination is subject, at the time of such
approval by shareholders, to the consent of any government or governmental
agency, the obtaining of such consent (either explicitly or implicitly by
consummation); excluding, however, such a Business Combination pursuant to which
(A) all or substantially all of the individuals and entities who were the
beneficial owners of the Outstanding Company Voting Securities immediately prior
to such Business Combination beneficially own, directly or indirectly, more than
60% of, respectively, the then outstanding shares of common stock and the
combined voting power of the then outstanding voting securities entitled to vote
generally in the election of directors, as the case may be, of the corporation
resulting from such Business Combination (including, without limitation, a
corporation that as a result of such transaction owns the Company or all or sub-
stantially all of the Company's assets either directly or through one or more
subsidiaries) in substantially the same proportions as their ownership,
immediately prior to such Business Combination of the Outstanding Company Voting
Securities, (B) no Person (excluding any employee benefit plan (or related
trust) of the Company or such corporation resulting from such Business
Combination) beneficially owns, directly or indirectly, 30% or more of,
respectively, the then outstanding shares of common stock of the corporation
resulting from such Business Combination or the combined voting power of the
then outstanding voting securities of such corporation except to the extent that
such ownership existed prior to the Business Combination and (C) at least a
majority of the members of the board of directors of the corporation resulting
from such Business Combination were members of the Incumbent Board at the time
of the execution of the initial agreement, or of the action of the Board,
providing for such Business Combination; or

          (iv)   approval by the shareholders of the Company of a complete
liquidation or dissolution of the Company.

     (e)  "Cause" means that, prior to any Termination by the Executive for Good
Reason, the Executive shall have:

          (i)    committed an intentional act of fraud, embezzlement, or theft
in connection with the Executive's duties or in the course of his employment
with the Company;

          (ii)   committed intentional wrongful damage to property of the
Company; or
<PAGE>
 
          (iii)  intentionally and wrongfully disclosed confidential information
of the Company; and any such act shall have been materially harmful to the
Company.

For purposes of this Agreement, no act on the part of the Executive shall be
deemed "intentional" if it was due primarily to an error in judgment or
negligence, but shall be deemed "intentional" only if done by the Executive not
in good faith and without reasonable belief that the Executive's action or
omission was in the best interests of the Company.

     (f)  "Date of Termination" means the date of receipt of the Notice of
Termination or any later date specified therein, as the case may be; provided,
however, that if the Executive is Terminated by the Company other than for Cause
or for disability pursuant to Section 2(a)(ii), the Date of Termination will be
the date on which the Executive receives the Notice of Termination from the
Company; and provided further, if the Executive is Terminated by reason of death
or disability pursuant to Section 2(a)(i) or 2(a)(ii), the Date of Termination
will be the last day of the month in which occurs the date of death or the
disability effective date, as the case may be.

     (g)  "Employee Benefits" means the perquisites, benefits and service credit
for benefits as provided under the plans and programs maintained by the Company,
including, but not limited to, plans and programs which are "employee benefit
plans" under Section 3(3) of the Employee Retirement Income  Security Act of
1974, as amended, and any amendment, or successor, to such plans or programs
(whether insured, funded or unfunded).

     (h)  "Good Reason" means the occurrence of any of the events listed in
Sections 2(b)(i) through 2(b)(vii), inclusive.

     (i)  "Incentive Pay" means an annual amount equal to the aggregate annual
bonus, in addition to Base Pay, made or to be made in regard to services
rendered in any calendar year or performance period pursuant to any bonus plan
of the Company.

     (j)  "Notice of Termination" means a written notice which (i) indicates the
specific provision in this Agreement relied upon, (ii) sets forth in reasonable
detail the facts and circumstances claimed to provide a basis for the
Termination under the provision so indicated, and (iii) if the effective date of
the Termination is other than the date of receipt of such notice, specifies the
effective date of Termination (which date will be not more than sixty (60) days
after the giving of such notice).  The failure by the Executive to set forth in
the Notice of Termination any fact or circumstance which contributes to a
showing that the Executive is
<PAGE>
 
entitled to the benefits intended to be provided by this Agreement will not
constitute a waiver of any right of the Executive hereunder or otherwise
preclude the Executive from later asserting such fact or circumstance in
enforcing the Executive's rights hereunder.

     (k)  "Severance Period" means the period of time commencing on the date of
an occurrence of a Change of Control and continuing until the earlier of (i) the
date which is two years following the occurrence of the Change of Control, and
(ii) the Executive's death.

     (l)  "Subsidiary" means an entity, at least a majority of the total voting
power of the then-outstanding voting securities of which is held, directly or
indirectly, by the Company and/or one or more other Subsidiaries or, for any
entity that is not a corporation, at least a majority of the then-outstanding
capital interests of which is so held.

     (m)  "Term" means (A) the period commencing on the date hereof and ending
on the second anniversary of the date hereof; provided, however, that commencing
on the date one year after the date hereof, and on each annual anniversary of
such date (such date and each annual anniversary thereof shall be hereinafter
referred to as the "Renewal Date"), unless previously terminated, the Term shall
be automatically extended so as to terminate two years from such Renewal Date,
unless at least sixty (60) days prior to the Renewal Date the Company shall give
notice to the Executive that the Term shall not be so extended, (B) if, prior to
a Change of Control, for any reason the Executive is Terminated or Terminates,
thereupon without further action the Term shall be deemed to have expired and
this Agreement will immediately terminate and be of no further effect, and (C)
in the event of a Change of Control, the Term will, without further action, be
considered to terminate at the expiration of the Severance Period.

     (n)  "Terminate" and correlative terms mean the termination of the
Executive's employment with the Company and any Affiliate or Subsidiary.

     (o)  "Warburg" means Warburg, Pincus Capital Partners, L.P., and/or any of
its affiliates.

2.   Termination Following a Change of Control:  (a)  If, during the Severance
     -----------------------------------------                                
Period, the Executive is Terminated, the Executive will be entitled to the
benefits provided by Sections 3 and 4 unless
<PAGE>
 
such termination is by reason of one or more of the following events:

          (i)    The Executive's death;

          (ii)   The permanent and total disability of the Executive as defined
in any long term disability plan of the Company, applicable to the Executive, as
in effect immediately prior to the Change of Control;

          (iii)  Cause; or

          (iv)   The Executive's voluntary Termination in circumstances in
which Good Reason does not exist.

     (b)  In the event of the occurrence of a Change of Control, the Executive
may Terminate during the Severance Period with the right to severance
compensation as provided in Sections 3 and 4 upon the occurrence of one or more
of the following events (regardless of whether any other reason, other than
Cause as hereinabove provided, for Termination exists or has occurred, including
without limitation other employment):

          (i)    An adverse change in the nature or scope of the authorities,
powers, functions, responsibilities, or duties attached to the position with the
Company, which the Executive held immediately prior to the Change of Control;

          (ii)   A reduction in the Executive's Base Pay as in effect
immediately prior to any Change of Control, or as it may have been increased
from time to time thereafter;

          (iii)  Any failure by the Company to continue in effect any plan or
arrangement providing Incentive Pay in which the Executive is participating at
the time of a Change of Control (or any other plans or arrangements providing
substantially similar benefits) or the taking of any action by the Company, any
Affiliate or Subsidiary which would adversely affect the Executive's
participation in any such plan or arrangement or reduce the Executive's benefits
under any such plan or arrangement in a manner inconsistent with the practices
of the Company prior to the Change of Control;

          (iv)   Any failure by the Company to continue in effect any Employee
Benefits in which the Executive is participating at the time of a Change of
Control (or any other plans or arrangements providing the Executive with
substantially similar benefits) or the taking of any action by the Company, an
Affiliate or Subsidiary which would adversely affect the Executive's
participation in or materially reduce the Executive's
<PAGE>
 
benefits under any Employee Benefits or deprive the Executive of any material
fringe benefit enjoyed by the Executive at the time of a Change of Control;

          (v)    The liquidation, dissolution, merger, consolidation, or
reorganization of the Company or transfer of all or substantially all of its
business and/or assets, unless the successor or successors (by liquidation,
merger, consolidation, reorganization, transfer, or otherwise) to which all or a
significant portion of its business and/or assets have been transferred
(directly or by operation of law) assumed all duties and obligations of the
Company under this Agreement pursuant to Section 9;

          (vi)   Without limiting the generality or effect of the foregoing, any
material breach of this Agreement by the Company or any successor thereto; or

          (vii)  Any action by the Company which causes the Executive's services
to be performed at a location which is more than thirty five (35) miles from the
location where the Executive was employed immediately preceding the date of the
Change of Control.

     (c)  Any Termination will be communicated by Notice of Termination
hereto given in accordance with Section 10 of this Agreement.

3.   Severance Compensation:  (a)  If, following the occurrence of a Change of
     ----------------------                                                   
Control, the Executive is Terminated by the Company during the Severance Period
other than in the circumstances set forth in Section 2(a)(i), 2(a)(ii), or
2(a)(iii), or if the Executive Terminates for Good Reason:

     (i)  The Company will pay to the Executive in a lump sum in cash within
five (5) business days after the later of the date on which the Company receives
the determination of the Accounting Firm required in Section 4 hereof or the
Date of Termination the aggregate of the amount (the "Severance Payment") equal
to two times the sum of (A) the Executive's Base Pay at the highest rate in
effect at any time within the 90-day period preceding the date the Notice of
Termination was given or, if higher, at the highest rate in effect at any time
within the 90-day period preceding the date of the first occurrence of a Change
of Control, and (B) an amount equal to the greatest amount of Incentive Pay
received by the Executive during any calendar year or portion thereof from and
<PAGE>
 
including the third calendar year prior to the first occurrence of a Change of
Control; and

     (ii) For the period of two years from the Date of Termination, the
Executive shall be eligible for participation in and shall receive all benefits
under such benefit plans, practices, policies and programs of the Company that
provide medical, prescription dental, or life insurance coverage, with the costs
of such participation to be paid by the Company to the same extent as prior to
the Executive's Termination.  In the event that such continued participation is
not allowed under the terms and provisions of such plans or programs, then in
lieu thereof, the Company shall acquire individual insurance policies providing
comparable coverage for the Executive; provided that if any such individual
coverage is unavailable, the Company shall pay to the Executive an amount equal
to the contributions that would have been made by the Company for such coverage
on the Executive's behalf if the Executive had remained in the employ of the
Company for the period referred to in the preceding sentence.

          (b)  There will be no right of set-off or counterclaim in respect of
any claim, debt, or obligation against any payment to or benefit for the
Executive provided for in this Agreement.

          (c)  Without limiting the rights of the Executive at law or in equity,
if the Company fails to make any payment or provide any benefit required to be
made or provided under this Agreement (including under this Section 3 or Section
6) on a timely basis, the Company will pay interest on the amount or value
thereof at an annualized rate of interest equal to the so-called composite
"prime rate" as quoted from time to time during the relevant period in the
Northeast Edition of The Wall Street Journal.  Such interest will be payable as
                     -----------------------                                   
it accrues on demand.  Any change in such prime rate will be effective on and as
of the date of such change.

          (d)  Notwithstanding any other provision hereof, the parties,
respective rights and obligations under this Section 3 and under Sections 4 and
6 will survive any termination or expiration of this Agreement following a
Change of Control or any Termination following a Change of Control for any
reason whatsoever.

4.   Excise and Other Taxes.  The Executive shall bear all expense of, and be
     ----------------------                                                  
solely responsible for, all federal, state, local or foreign taxes due with
respect to any payment received hereunder, including, without limitation, any
excise tax imposed by Section 4999 of the Internal Revenue Code of 1986, as
amended (the Code); provided, however, that all payments under this Agreement
shall be reduced to the extent necessary so that no portion thereof shall be
subject to the excise tax imposed by Section 4999 of the Code but only if, by
reason of such reduction, the net after-tax benefit
<PAGE>
 
received by the Executive shall exceed the net after-tax benefit received by the
Executive if no such reduction was made.  For purposes of this Section 4, "net
after-tax benefit" shall mean (i) the total of all payments and the value of all
benefits which the Executive receives or is then entitled to receive from the
Company that would constitute "parachute payments" within the meaning of Section
280G of the Code, less (ii) the amount of all federal, state and local income
taxes payable with respect to the foregoing calculated at the maximum marginal
income tax rate for each year in which the foregoing shall be paid to the
Executive (based on the rate in effect for such year as set forth in the Code
as in effect at the time of the first payment of the foregoing), less (iii) the
amount of excise taxes imposed with respect to the payments and benefits
described in (i) above by Section 4999 of the Code.  The foregoing determination
will be made by a nationally recognized accounting firm (the "Accounting Firm")
selected by the Executive and reasonably acceptable to the Company (which may
be, but will not be required to be, the Company's independent auditors).  The
Executive will direct the Accounting Firm to submit its determination and
detailed supporting calculations to both the Company and the Executive within
fifteen (15) days after the Date of Termination.  If the Accounting Firm
determines that such reduction is required by this Section 4, the Company shall
pay such reduced amount to the Executive in accordance with Section 3(a).  If
the Accounting Firm determines that no reduction is necessary under this Section
4, it will, at the same time as it makes such determination, furnish the
Company and the Executive an opinion that the Executive will not be liable for
any excise tax under Section 4999 of the Code.  The Company and the Executive
will each provide the Accounting Firm access to and copies of any books,
records, and documents in the possession of the Company or the Executive, as the
case may be, reasonably requested by the Accounting Firm, and otherwise
cooperate with the Accounting Firm in connection with the preparation and
issuance of the determinations and calculations contemplated by this Section 4.
The fees and expenses of the Accounting Firm for its services in connection with
the determinations and calculations contemplated by this Section 4 will be
borne by the Company.

5.   No Mitigation Obligation:  The Company hereby acknowledges that it will be
     ------------------------                                                  
difficult, and may be impossible, for the Executive to find reasonably
comparable employment following the Date of Termination.  The payment of the
severance compensation by the Company to the Executive in accordance with the
terms of this Agreement will be liquidated damages, and the Executive will not
be required to mitigate the amount of any payment provided for in this
<PAGE>
 
Agreement by seeking other employment or otherwise, nor will any profits,
income, earnings, or other benefits from any source whatsoever create any
mitigation, offset, reduction, or any other obligation on the part of the
Executive hereunder or otherwise.

6.   Legal Fees and Expenses:  If the Company has failed to comply with any of
     -----------------------                                                  
its obligations under this Agreement or in the event that the Company or any
other person takes or threatens to take any action to declare this Agreement
void or unenforceable, or institutes any litigation or other action or
proceeding designed to deny, or to recover from, the Executive the benefits
provided or intended to be provided to the  Executive hereunder, the Company
irrevocably authorizes the Executive from time to time to retain counsel of the
Executive's choice, at the expense of the Company, to advise and represent the
Executive in connection with any such interpretation, enforcement, or defense,
including without limitation the initiation or defense of any litigation or
other legal action, whether by or against the Company or any member of the
Board, officer, stockholder, or other person or entity affiliated with the
Company, in any jurisdiction.  The Company will pay and be solely financially
responsible for any and all attorneys' and related fees and expenses incurred by
the Executive in connection with such litigation.

7.   Employment Rights:  Nothing expressed or implied in this Agreement will
     -----------------                                                      
create any right or duty on the part of the Company or the Executive to have the
Executive remain in the employment of the Company, or any Affiliate or
Subsidiary prior to or following any Change of Control.

8.   Withholding of Taxes:  The Company may withhold from any amounts payable
     --------------------                                                    
under this Agreement all federal, state, city, or other taxes as the Company is
required to withhold pursuant to any law or government regulation or ruling.

9.   Successors and Binding Agreement:  (a)  The Company will require any
     --------------------------------                                    
successor (whether direct or indirect, by purchase, merger, consolidation,
reorganization, or otherwise) to all or substantially all of the business and/or
assets of the Company, by agreement in form and substance satisfactory to the
Executive, expressly to assume and agree to perform this agreement in the same
manner and to the same extent the Company would be required to perform if no
such succession had taken place.  This Agreement will be binding upon and inure
to the benefit of the Company and any successor to the Company, including,
without limitation, any persons acquiring directly or indirectly all or
substantially all of the business and/or assets of the Company, whether by
purchase, merger, consolidation, reorganization, or otherwise (and such
successor will thereafter be deemed the "Company" for the purposes of this
Agreement), but will not otherwise be assignable,
<PAGE>
 
transferable, or delegable by the Company.

     (b)  This Agreement will inure to the benefit of and be enforceable by the
Executive's personal or legal representatives, executors, administrators,
successors, heirs, distributees, and/or legatees.

     (c)  This Agreement is personal in nature and neither of the parties hereto
will, without the consent of the other, assign, transfer, or delegate this
Agreement or any rights or  obligations hereunder except as expressly provided
in Sections 9(a) and 9(b). Without limiting the generality or effect of the
foregoing, the Executive's right to receive payments hereunder will not be
assignable, transferable, or delegable, whether by pledge, creation of a
security interest, or otherwise, other than by a transfer by will or by the laws
of descent and distribution and, in the event of any attempted assignment or
transfer contrary to this Section 9(c), the Company will have no liability to
pay any amount so attempted to be assigned, transferred, or delegated.

10.  Notices:  For all purposes of this Agreement, all communications,
     -------                                                          
including, without limitation, notices, consents, requests, or approvals,
required or permitted to be given hereunder will be in writing and will be
deemed to have been duly given when hand delivered or dispatched by electronic
facsimile transmission (with receipt thereof orally confirmed), or two business
days after having been mailed by United States registered or certified mail,
return receipt requested, postage prepaid, or one business day after having been
sent by a nationally recognized overnight courier service, addressed to the
Company (to the attention of the General Counsel of the Company) at its
principal executive office and to the Executive at the Executive's principal
residence, or to such other address as any party may have furnished to the other
in writing and in accordance herewith, except that notices of changes of address
will be effective only upon receipt.

11.  Governing Law:  The validity, interpretation, construction, and performance
     -------------                                                              
of this Agreement will be governed by and construed in accordance with the
substantive laws of the State of Connecticut, without giving effect to the
principles of conflict of laws of such State, to the extent not preempted by
applicable federal law.

12.  Validity:  If any provision of this Agreement or the application of any
     --------                                                               
provision hereof to any person or circumstances is held invalid, unenforceable,
or otherwise illegal, the remainder
<PAGE>
 
of this Agreement and the application of such provision to any other person or
circumstances will not be affected, and the provision so held to be invalid,
unenforceable, or otherwise illegal will be reformed to the extent (and only to
the extent) necessary to make it enforceable, valid, or legal.

13.  Non-Exclusivity of Rights:  Nothing in this Agreement will prevent or limit
     -------------------------                                                  
the Executive's present or future participation in any benefit, bonus,
incentive, or other plan or program provided by the Company or any Affiliate or
Subsidiary for which the Executive may qualify, nor will this  Agreement in any
manner limit or otherwise affect such rights as the Executive may have under any
stock option or other agreements with the Company or any Affiliate or
Subsidiary.  Amounts or benefits which are vested or which the Executive is
otherwise entitled to receive under any plan or program of the Company at or
subsequent to the Date of Termination will be payable in accordance with such
plan or program, except as otherwise expressly provided in this Agreement;
provided, however, that any amounts received by the Executive pursuant to this
Agreement shall be in lieu of any benefits which the Executive is entitled to
receive or may become entitled to receive under any reduction-in-force or
severance pay plan or practice which the Company now has in effect or may
hereafter put into effect, any other benefits to which the Executive may be
entitled under any individual agreement of employment with the Company which
would provide a benefit to the Executive upon the occurrence of a Change of
Control of the Company, and any severance benefits required under federal or
state law to be paid to the Executive.

14.  Miscellaneous:  (a) No provision of this Agreement may be modified, waived,
     ------------- 
or discharged unless such waiver, modification, or discharge is agreed to in
writing signed by the Executive and the Company. No waiver by either party
hereto at any time of any breach by the other party hereto or compliance with
any condition or provision of this Agreement to be performed by such other party
will be deemed a waiver of similar or dissimilar provisions or conditions at the
same or at any prior or subsequent time. No agreements or representations, oral
or otherwise, express or implied with respect to the subject matter hereof have
been made by either party which are not set forth expressly in this Agreement.
References to Sections are to references to Sections of this Agreement.

     (b)  The Executive and the Company acknowledge that this Agreement
supersedes any other agreement between them concerning the subject matter
hereof, other than the Employment Agreement between the Executive and the
Company dated as of November 4, 1996.
<PAGE>
 
          IN WITNESS WHEREOF, the parties have caused this Agreement to be duly
executed and delivered as of the date first above written.

                              ADVO, Inc.



                              By /s/ Robert Kamerschen
                                -------------------------------    
                                Robert Kamerschen
 
                               
                                /s/ Gary M. Mulloy
                                ----------------------------
                                Gary M. Mulloy