<PAGE>

                                                                   EXHIBIT 10.15

THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 AS
AMENDED, OR ANY STATE SECURITIES LAWS. THEY MAY NOT BE SOLD, OFFERED FOR SALE,
PLEDGED, OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT
RELATED THERETO OR AN OPINION OF COUNSEL (WHICH MAY BE COMPANY COUNSEL)
REASONABLY SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY APPLICABLE STATE SECURITIES
LAWS.

                               WARRANT AGREEMENT

      To Purchase Shares of the Series A Convertible Preferred Stock of

                                  eDOCS, INC.

               Dated as of March 31, 1999 (the "Effective Date")

     WHEREAS, eDocs, Inc., a Delaware corporation (the "Company") has entered
into a Subordinated Loan and Security Agreement dated as of March 31, 1999, and
related Subordinated and Promossory Note(s) (collectively, the "Loans") with
Comdisco, Inc., a Delaware corporation (the "Warrantholder"); and

     WHEREAS, the Company desires to grant to Warrantholder, in consideration
for such Loans, the right to purchase shares of its Series A Convertible
Preferred Stock;

     NOW, THEREFORE, in consideration of the Warrantholder executing and
delivering such Loans and in consideration of mutual covenants and agreements
contained herein, the Company and Warrantholder agree as follows:

1.  GRANT OF THE RIGHT TO PURCHASE PREFERRED STOCK.
    ----------------------------------------------

    The Company hereby grants to the Warrantholder, and the Warrantholder is
entitled, upon the terms and subject to the conditions hereinafter set forth, to
subscribe to and purchase, from the Company, such number of fully paid and non-
assessable shares of the Company's Series A Convertible Preferred Stock
("Preferred Stock") at a purchase price equal to Three Hundred Ninety Thousand
Dollars ($390,000.00) divided by the Exercise Price. The Exercise Price shall be
defined as the lesser of (i) the average of $1.00 per share (the "Last Round
Price") and the price per share paid in the Next Round or (ii) the price per
share based on a Forty-Five Million Dollar Pre-Money Valuation Price (the
"Exercise Price"). Notwithstanding the foregoing, in no event shall the initial
Exercise Price be less than $1.00 per share unless subsequently adjusted in
accordance with Section 8 hereof. "Forty-Five Million Dollar Pre-Money Valuation
Price" shall be calculated by dividing Forty-Five Million Dollars
($45,000,000.00) by the number of fully diluted shares of the Company's (A)
issued and outstanding Common Stock, (B) issued and outstanding shares of
Preferred Stock and warrants, as converted to Common Stock, and (C) options
issued or reserved for issuance, as exercised into Common Stock outstanding
immediately prior to the closing of the Next Round. "Next Round" shall be
defined as (i) preferred stock financing of at least $2,000,000, (ii) the sale,
conveyance disposal, or encumbrance of all or substantially all of the Company's
property or business or Company's merger into or consolidation with any other
corporation (other than a wholly-owned subsidiary corporation) or any other
transaction or series of related transactions in which more than fifty percent
(50%) of the voting power of Company is disposed of ("Merger Event"), provided
that a Merger Event shall not apply to a merger effected exclusively for the
purpose of changing the domicile of the company or (iii) an initial public
offering of the Company's Common Stock which such public offering has been
declared effective by the SEC. The number and purchase price of such shares are
subject to adjustment as provided in Section 8 hereof.

2.  TERM OF THE WARRANT AGREEMENT
    -----------------------------

    Except as otherwise provided for herein, the terms of this Warrant
Agreement and the right to purchase Preferred Stock as granted herein shall
commence on the Effective Date and shall be exercisable for a period of (i)
seven (7) years from the Effective Date or (ii) or two (2) years from the
effective date of the Company's initial public offering, whichever is earlier.









<PAGE>

     If at any time all of the outstanding shares of Preferred Stock have been
converted to shares of the Company's Common Stock, then, from and after the date
of such conversion, this Warrant Agreement shall no longer be exercisable for
Preferred Stock, but shall represent the right to acquire that number of shares
of Common Stock as shall be equal to the number of shares issuable upon
conversion of the Preferred Stock which would have been issued on exercise of
this Warrant Agreement had such exercise occurred immediately prior to such
conversion.

3.   EXERCISE OF THE PURCHASE RIGHTS.
     -------------------------------

     The purchase rights set forth in this Warrant Agreement are exercisable by
the Warrantholder, in whole or in part, at any time, or from time to time, prior
to the expiration of the term set forth in Section 2 above, by tendering to the
Company at its principal office a notice of exercise in the form attached hereto
as Exhibit I (the "Notice of Exercise"), duly completed and executed. Promptly
upon receipt of the Notice of Exercise and the payment of the purchase price in
accordance with the terms set forth below, and in no event later than twenty-one
(21) days thereafter, the Company shall issue to the Warrantholder a certificate
for the number of shares of Preferred Stock purchased and shall execute the
acknowledgment of exercise in the form attached hereto as Exhibit II (the
"Acknowledgment of Exercise") indicating the number of shares which remain
subject to future purchases, if any.

    The Exercise Price may be paid at the Warrantholder's election either (i) by
cash or check, or (ii) after March 31, 2001, by surrender ("Net Issuance") as
determined below. Notwithstanding the foregoing limitation, the Warrantholder
may exercise the Warrant Agreement by Net Issuance at any time after the
Effective Date hereof in the case of an initial public offering of the Company's
equity securities or a Merger Event as defined in Section 8(a) hereof. If the
Warrantholder elects the Net Issuance method, the Company will issue Preferred
Stock in accordance with the following formula:


                X=Y(A-B)
                  ------
                    A

     Where: X= the number of shares of Preferred Stock to be issued to the
                     Warrantholder.

            Y= the number of shares of Preferred Stock requested to be
                    exercised under this Warrant Agreement.

            A= the fair market value of one (1) share of Preferred Stock.

            B= the Exercise Price.

     For purposes of the above calculation, current fair market value of
Preferred Stock shall mean with respect to each share of Preferred Stock:

               (i) if the exercise is in connection with an initial public
     offering of the Company's Common Stock, which for purposes of this
     Agreement shall mean the delivery of a Notice of Exercise within twenty
     (20) days of the first filing by Borrower of a Registration Statement with
     the Securities Exchange Commission and if the Company's Registration
     Statement relating to such public offering has been declared effective by
     the SEC, then the fair market value per share shall be the product of (x)
     the initial "Price to Public" specified in the final prospectus with
     respect to the offering and (y) the number of shares of Common Stock into
     which this Warrant is convertible at the time of such exercise; and

               (ii) if this Warrant is exercised after, and not in connection
     with the Company's initial public offering, and;

                     (a) if traded on a securities exchange, the fair market
               value shall be deemed to be the product of (x) the average of the
               closing prices over a twenty-one (21) day period ending three
               days before the day the current fair market value of the
               securities is being determined and (y) the number of shares of
               Common Stock into which this Warrant is convertible at the time
               of such exercise; or

                     (b) if actively traded over-the-counter, the fair market
               value shall be deemed to be the product of (x) the average of the
               closing bid and asked prices quoted on the NASDAQ system (or
               similar system) over the twenty-one (21) day period ending three
               days before the day the


                                      -2-






<PAGE>

               current fair market value of the securities is being determined
               and (y) the number of shares of Common Stock into which this
               Warrant is convertible at the time of such exercise;

               (iii) if at any time the Common Stock is not listed on any
    securities exchange or quoted in the NASDAQ System or the over-the-counter
    market, the current fair market value of Preferred Stock shall be the
    product of (x) the highest price per share which the Company could obtain
    from a willing buyer (not a current employee or director) for shares of
    Common Stock sold by the Company, from authorized but unissued shares, as
    determined in good faith by its Board of Directors and (y) the number of
    shares of Common Stock into which each share of Preferred Stock is
    convertible at the time of such exercise, unless the Company shall become
    subject to a merger, acquisition or other consolidation pursuant to which
    the Company is not the surviving party, in which case the fair market value
    of Preferred Stock shall be deemed to be the value received by the holders
    of the Company's Preferred Stock on a common equivalent basis pursuant to
    such merger or acquisition.

    Upon partial exercise by either cash or Net Issuance, the Company shall
promptly issue an amended Warrant Agreement representing the remaining number of
shares purchasable hereunder. All other terms and conditions of such amended
Warrant Agreement shall be identical to those contained herein, including, but
not limited to the Effective Date hereof.

4.  RESERVATION OF SHARES.
    ---------------------

    (a) Authorization and Reservation of Shares. During the term of this Warrant
        ---------------------------------------
Agreement, the Company will at all times have authorized and reserved a
sufficient number of shares of its Preferred Stock to provide for the exercise
of the rights to purchase Preferred Stock as provided for herein.

    (b) Registration of Listing. If any shares of Preferred Stock required to
        -----------------------
be reserved hereunder require registration with or approval of any governmental
authority under any Federal or State law (other than any registration under the
Securities Act of 1933, as amended ("1933 Act"), as then in effect, or any
similar Federal statute then enforced, or any state securities law, required by
reason of any transfer involved in such conversion), or listing on any domestic
securities exchange, before such shares may be issued upon conversion, the
Company will, at its expense and as expeditiously as possible, use its best
efforts to cause such shares to be duly registered, listed or approved for
listing on such domestic securities exchange, as the case may be.

5.  NO FRACTIONAL SHARES OR SCRIP.
    -----------------------------

    No fractional shares or scrip representing fractional shares shall be
issued upon the exercise of the Warrant, but in lieu of such fractional shares
the Company shall make a cash payment therefor upon the basis of the Exercise
Price then in effect.

6.  NO RIGHTS AS SHAREHOLDER.
    ------------------------

    This Warrant Agreement does not entitle the Warrantholder to any voting
rights or other rights as a shareholder of the Company prior to the exercise of
the Warrant.

7.  WARRANTHOLDER REGISTRY.
    ----------------------

    The Company shall maintain a registry showing the name and address of the
registered holder of this Warrant Agreement.

8.  ADJUSTMENT RIGHTS.
    -----------------

    The purchase price per share and the number of shares of Preferred Stock
purchasable hereunder are subject to adjustment, except in the case where an
adjustment for the following matters is made to the shares of Preferred Stock or
the shares of Common Stock issuable upon exercise of the conversion of the
Preferred Stock in accordance with the terms of the Borrower's Certificate of
Incorporation, as follows. Notwithstanding the foregoing, solely with respect to
the shares of Preferred Stock or Common Stock then issuable upon exercise of
this Warrant, such adjustments shall apply regardless of whether Warrantholder
is a warrantholder or shareholder at the time of any dilutive issuance.

                                      -3-
<PAGE>

        (a) Merger and Sale of Assets. If at any time there shall be a capital
            -------------------------
reorganization of the shares of the Company's stock (other than a combination,
reclassification, exchange or subdivision of shares otherwise provided for
herein), or a merger or consolidation of the Company with or into another
corporation whether or not the Company is the surviving corporation, or the sale
of all or substantially all of the Company's properties and assets to any other
person (hereinafter referred to as a "Merger Event"), then, as a part of such
Merger Event, lawful provision shall be made so that the Warrantholder shall
thereafter be entitled to receive, upon exercise of the Warrant, the number of
shares of preferred stock or other securities of the successor corporation
resulting from such Merger Event, equivalent in value to that which would have
been issuable if Warrantholder had exercised this Warrant immediately prior to
the Merger Event. In any such case, appropriate adjustment (as determined in
good faith by the Company's Board of Directors) shall be made in the application
of the provisions of this Warrant Agreement with respect to the rights and
interest of the Warrantholder after the Merger Event to the end that the
provisions of this Warrant Agreement (including adjustments of the Exercise
Price and number of shares of Preferred Stock purchasable) shall be applicable
to the greatest extent possible.

        (b) Reclassification of Shares. If the Company at any time shall, by
            --------------------------
combination, reclassification, exchange or subdivision of securities or
otherwise, change any of the securities as to which purchase rights under this
Warrant Agreement exist into the same or a different number of securities of any
other class or classes, this Warrant Agreement shall thereafter represent the
right to acquire such number and kind of securities as would have been issuable
as the result of such change with respect to the securities which were subject
to the purchase rights under this Warrant Agreement immediately prior to such
combination, reclassification, exchange, subdivision or other change.

        (c) Subdivision or Combination of Shares. If the Company at any time
            ------------------------------------
shall combine or subdivide its Preferred Stock, the Exercise Price shall be
proportionately decreased in the case of a subdivision, or proportionately
increased in the case of a combination.

        (d) Stock Dividends. If the Company at any time shall pay a dividend
            ---------------
payable in, or make any other distribution (except any distribution specifically
provided for in the foregoing subsections (a) or (b)) of the Company's Preferred
Stock, then the Exercise Price shall be adjusted, from and after the record date
of such dividend or distribution, to that price determined by multiplying the
Exercise Price in effect immediately prior to such record date by a fraction (i)
the numerator of which shall be the total number of all shares of the Company's
Preferred Stock outstanding immediately prior to such dividend or distribution,
and (ii) the denominator of which shall be the total number of all shares of the
Company's Preferred Stock outstanding immediately after such dividend or
distribution. The Warrantholder shall thereafter be entitled to purchase, at the
Exercise Price resulting from such adjustment, the number of shares of Preferred
Stock (calculated to the nearest whole share) obtained by multiplying the
Exercise Price in effect immediately prior to such adjustment by the number of
shares of Preferred Stock issuable upon the exercise hereof immediately prior to
such adjustment and dividing the product thereof by the Exercise Price resulting
from such adjustment.

      (e) Antidilution Rights. Additional antidilution rights applicable to the
          -------------------
Preferred Stock purchasable hereunder are as set forth in the Company's
Certificate of Incorporation, as amended through the Effective Date, a true and
complete copy of which is attached hereto as Exhibit IV (the "Charter"). The
Company shall promptly provide the Warrantholder with any restatement,
amendment, modification or waiver of the Charter. The Company shall provide
Warrantholder with prior written notice of any issuance of its stock or other
equity security to occur after the Effective Date of this Warrant, which notice
shall include (a) the price at which such stock or security is to be sold, (b)
the number of shares to be issued, and (c) such other information as necessary
for Warrantholder to determine if a dilutive event has occurred. Such written
notice shall not be required where any such issuance will not result in an
adjustment to the shares of Preferred Stock. This section 8(e) shall terminate
upon the date that the Company's Registration Statement relating to its initial
public offering of its Common Stock has been declared effective by the SEC.

      (f) Notice of Adjustments. If: (i) the Company shall declare any dividend
          ---------------------
or distribution upon its stock, whether in cash, property, stock or other
securities: (ii) the Company shall offer for subscription prorata to the holders
of any class of its Preferred or other convertible stock any additional shares
of stock of any class or other rights; (iii) there shall be any Merger Event;
(iv) there shall be an initial public offering; or (v) there shall be any
voluntary dissolution, liquidation or winding up of the Company; then, in
connection with each such event, the Company shall send to the Warrantholder:
(A) at least twenty (20) days' prior written notice of the date on which the
books of the Company shall close or a record shall be taken for such dividend,
distribution, subscription rights (specifying the date on which the holders of
Preferred Stock shall be entitled thereto) or for determining rights to vote in
respect of such Merger Event,

                                      -4-

<PAGE>

dissolution, liquidation or winding up, at least twenty (20) days' prior written
notice of the date when the same shall take place (and specifying the date on
which the holders of Preferred Stock shall be entitled to exchange their
Preferred Stock for securities or other property deliverable upon such Merger
Event dissolution, liquidation or winding up); and (C) in the case of a public
offering, the Company shall give the Warrantholder at least twenty (20) days
written notice prior to the effective date thereof. This Section 8(f) shall
terminate upon the date that the Company's Registration Statement relating to
its initial public offering of its Common Stock has been declared effective by
the SEC.

        Each such written notice shall set forth, in reasonable detail and to
the extent applicable, (i) the event requiring the adjustment, (ii) the amount
of the adjustment, (iii) the method by which such adjustment was calculated,
(iv) the Exercise Price, and (v) the number of shares subject to purchase
hereunder after giving effect to such adjustment, and shall be given by first
class mail, postage prepaid, addressed to the Warrantholder, at the address as
shown on the books of the Company.

        (g) Timely Notice. Failure to timely provide such notice required by
            -------------
subsection (g) above shall entitle Warrantholder to retain the benefit of the
applicable notice period notwithstanding anything to the contrary contained in
any insufficient notice received by Warrantholder. The notice period shall begin
on the date Warrantholder actually receives a written notice containing all the
information specified above.

9. REPRESENTATIONS, WARRANTIES AND COVENANTS OF THE COMPANY.
   --------------------------------------------------------

       (a) Reservation of Preferred Stock. The Preferred Stock issuable upon
           ------------------------------
exercise of the Warrantholder's rights has been duly and validly reserved and,
when issued in accordance with the provisions of this Warrant Agreement, will be
validly issued, fully paid and non-assessable, and will be free of any taxes,
liens, charges or encumbrances of any nature whatsoever, provided, however, that
the Preferred Stock issuable pursuant to this Warrant Agreement may be subject
to restrictions on transfer under state and/or Federal securities laws. The
Company has made available to the Warrantholder true, correct and complete
copies of its Charter and Bylaws, as amended. The issuance of certificates for
shares of Preferred Stock upon exercise of the Warrant Agreement shall be made
without charge to the Warrantholder for any issuance tax in respect thereof, or
other cost incurred by the Company in connection with such exercise and the
related issuance of shares of Preferred Stock. The Company shall not be required
to pay any tax which may be payable in respect of any transfer involved and the
issuance and delivery of any certificate in a name other than that of the
Warrantholder.


       (b) Due Authority. The execution and delivery by the Company of this
           -------------
Warrant Agreement and the performance of all obligations of the Company
hereunder, including the issuance to Warrantholder of the right to acquire the
shares of Preferred Stock, have been duly authorized by all necessary corporate
action on the part of the Company, and the Leases and this Warrant Agreement are
not inconsistent with the Company's Charter or Bylaws, do not contravene any law
or governmental rule, regulation or order applicable to it, do not and will not
contravene any provision of, or constitute a default under, any indenture,
mortgage contract or other instrument to which it is a party or by which it is
bound, and the Leases and this Warrant Agreement constitute legal, valid and
binding agreements of the Company, enforceable in accordance with their
respective terms.


        (c) Consents and Approvals. No consent or approval of, giving of notice
            ----------------------
to, registration with, or taking of any other action in respect of any state,
Federal or other governmental authority or agency is required with respect to
the execution, delivery and performance by the Company of its obligations under
this Warrant Agreement, except for the filing of notices pursuant to Regulation
D under the 1933 Act and any filing required by applicable state securities law,
which filings, will be effective by the time required thereby.

        (d) Issued Securities. All issued and outstanding shares of Common
            -----------------
Stock, Preferred Stock or any other securities of the Company have been duly
authorized and validly issued and are fully paid and nonassessable. All
outstanding shares of Common Stock, Preferred Stock and any other securities
were issued in full compliance with all Federal and state securities laws. In
addition, upon the filing by the Company of a Certificate of Amendment to its
Certificate of Incorporation, and such filing shall be no later than the
Effective Date:

               (i) The authorized capital of the Company consists of
(A) 11,570,000 shares of Common Stock, of which 5,000,000 shares are issued
and outstanding, and (B) 4,570,000 shares of preferred stock, of which
4,570,000 shares have been designated as Series A Convertible Preferred Stock
and 4,000,000 of which are issued and outstanding and are convertible into
4,000,000 shares of Common Stock at $1.00 per share.

                                      -5-

<PAGE>

               (ii) The Company has reserved (A) 1,500,000 shares of Common
       Stock for issuance under its 1998 Stock Option Plan, under which 796,625
       options are outstanding as of February 28, 1999 at any average price of
       $0.10 per share. There are no other options, warrants, conversion
       privileges or other rights presently outstanding to purchase or otherwise
       acquire any authorized but unissued shares of the Company's capital stock
       or other securities of the Company.


               (iii) Except as provided in Schedule 1 attached hereto, no
       shareholder of the Company has preemptive rights to purchase new
       issuances of the Company's capital stock.

       (e) Insurance. The Company has in full force and effect insurance
           ---------
policies, with extended coverage, insuring the Company and its property and
business against such losses and risks, and in such amounts, as are customary
for corporations engaged in a similar business and similarly situated and as
otherwise may be required pursuant to the terms of any other contract or
agreement.

       (f) Other Commitments to Register Securities. Except as set forth in a
           ----------------------------------------
Registration Rights Agreement, dated as of May 22, 1998, the Company is not,
pursuant to the terms of any other agreement currently in existence, under any
obligation to register under the 1933 Act any of its presently outstanding
securities or any of its securities which may hereafter be issued.

       (g) Exempt Transaction. Subject to the accuracy of the Warrantholder's
           ------------------
representations in Section 10 hereof, the issuance of the Preferred Stock upon
exercise of this Warrant will constitute a transaction exempt from (i) the
registration requirements of Section 5 of the 1933 Act, in reliance upon Section
4(2) thereof, and (ii) the qualification requirements of the applicable state
securities laws.

       (h) Compliance with Rule 144. At the written request of the
           ------------------------
Warrentholder, who proposes to sell Preferred Stock issuable upon the exercise
of the Warrant in compliance with Rule 144 promulgated by the Securities and
Exchange Commission, the Company shall furnish to the Warrantholder, within ten
days after receipt of such request, a written statement confirming the Company's
compliance with the filing requirements of the Securities and Exchange
Commission as set forth in such Rule, as such Rule may be amended from time to
time.

10.    REPRESENTATIONS AND COVENANTS OF THE WARRANTHOLDER.
       --------------------------------------------------

       This Warrant Agreement has been entered into by the Company in reliance
upon the following representations and covenants of the Warrantholder:


       (a) Investment Purpose. The right to acquire Preferred Stock or the
           ------------------
Preferred Stock issuable upon exercise of the Warrantholder's rights contained
herein will be acquired for investment and not with a view to the sale or
distribution of any part thereof, and the Warrantholder has no present intention
of selling or engaging in any public distribution of the same except pursuant to
a registration or exemption.

       (b) Private Issue. The Warrantholder understands (i) that the Preferred
           -------------
Stock issuable upon exercise of this Warrant is not registered under the 1933
Act or qualified under applicable state securities laws on the ground that the
issuance contemplated by this Warrant Agreement will be exempt from the
registration and qualifications requirements thereof, and (ii) that the
Company's reliance on such exemption is predicated on the representations set
forth in this Section 10.

       (c) Disposition of Warrantholder's Rights. In no event will the
           -------------------------------------
Warrantholder make a disposition of any of its rights to acquire Preferred Stock
or Preferred Stock issuable upon exercise of such rights unless and until (i) it
shall have notified the Company of the proposed disposition, and (ii) if
requested by the Company, it shall have furnished the Company with an opinion of
counsel (which counsel may either be inside or outside counsel to the
Warrantholder) satisfactory to the Company and its counsel to the effect that
(A) appropriate action necessary for compliance with the 1933 Act has been
taken, or (B) an exemption from the registration requirements of the 1933 Act is
available. Notwithstanding the foregoing, the restrictions imposed upon the
transferability of any of its rights to acquire Preferred Stock or Preferred
Stock issuable on the exercise of such rights do not apply to transfers from the
beneficial owner of any of the aforementioned securities to its nominee or from
such nominee to its beneficial owner, and shall terminate as to any particular
share of Preferred Stock when (1) such security shall have been effectively
registered under the 1933 Act and sold by the holder thereof in accordance with
such registration or (2) such security shall have been sold without registration
in compliance with Rule 144 under the 1933 Act, or (3) a letter shall have been
issued to the Warrantholder at its request by the staff of the Securities and
Exchange Commission or a ruling shall have been issued to the Warrantholder at
its request by such Commission stating that no action shall be

                                      -6-




<PAGE>

recommended by such staff or taken by such Commission, as the case may be, if
such security is transferred without registration under the 1933 Act in
accordance with the conditions set forth in such letter or ruling and such
letter or ruling specifies that no subsequent restrictions on transfer are
required. Whenever the restrictions imposed hereunder shall terminate, as
hereinabove provided, the Warrantholder or holder of a share of Preferred Stock
then outstanding as to which such restrictions have terminated shall be entitled
to receive from the COmpany, without expense to such holder, one or more new
certificates for the Warrant or for such shares of Preferred Stock not bearing
any restrictive legend.

       (d) Financial Risk. The Warrantholder has such knowledge and experience
           --------------
in financial and business matters as to be capable of evaluating the merits and
risks of its investment, and has the ability to bear the economic risks of its
investment.

       (e) Risk of No Registration. The Warrantholder understands that if the
           -----------------------
Company does not register with the Securities and Exchange Commission pursuant
to Section 12 of the 1934 Act (the "1934 Act"), or file reports pursuant to
Section 15(d), of the 1934 Act, or if a registration statement covering the
securities under the 1933 Act is not in effect when it desires to sell (i) the
rights to purchase Preferred Stock pursuant to this Warrant Agreement, or (ii)
the Preferred Stock issuable upon exercise of the right to purchase, it may be
required to hold such securities for an indefinite period. The Warrantholder
also understands that any sale of its rights of the Warrantholder to purchase
Preferred Stock or Preferred Stock which might be made by it in reliance upon
Rule 144 under the 1933 Act may be made only in accordance with the terms and
conditions of that Rule.

       (f) Accredit Investor. Warrantholder is an "accredited investor" within
           -----------------
the meaning of the Securities and Exchange Rule 501 of Regulation D, as
presently in effect.

11.    RIGHT OF FIRST OFFER.
       --------------------

       Pursuant to Amendment No. 1 to the Stockholders Agreement dated as of
March 31, 1999, the Warrantholder shall have the rights of first offer granted
therein.

12.    TRANSFERS.
       ---------


       Subject to the terms and conditions contained in Section 10 hereof, this
Warrant Agreement and all rights hereunder are transferable in whole or in part
by the Warrantholder and any successor transferee, provided, however, in no
event shall the number of transfers of the rights and interests in all of the
Warrants exceed three (3) transfers. The transfer shall be recorded on the books
of the Company upon receipt by the Company of a notice of transfer in the form
attached hereto as Exhibit III (the "Transfer Notice"), at its principal offices
and the payment to the Company of all transfer taxes and other governmental
charges imposed on such transfer.

13.    MISCELLANEOUS.
      -------------

       (a) Effective Date. The provisions of this Warrant Agreement shall be
           --------------
construed and shall be given effect in all respects as if it had been executed
and delivered by the Company on the date hereof. This Warrant Agreement shall be
binding upon any successors or assigns of the Company.

       (b) Attorney's Fees. In any litigation, arbitration or court proceeding
           ---------------
between the Company and the Warrantholder relating hereto, the prevailing party
shall be entitled to attorney's fees and expenses and all costs of proceedings
incurred in enforcing this Warrant Agreement.

       (c) Governing Law. This Warrant Agreement shall be governed by and
           -------------
construed for all purposes under and in accordance with the laws of the State of
Illinois.

       (d) Counterparts. This Warrant Agreement may be executed in two or more
           ------------
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

       (e) Notices. Any notice required or permitted hereunder shall be given in
           -------
writing and shall be deemed effectively given upon personal delivery, facsimile
transmission (provided that the original is sent by personal delivery or mail as
hereinafter set forth) or seven (7) days after deposit in the United States
mail, by registered or certified mail, addressed (i) to the Warrantholder at
6111 North River Road, Rosemont, Illinois 60018, Attention: Venture Lease
Administration, cc: Legal Department, Attention: General Counsel, (and/or, if by
facsimile, (847) 518-5465 and (847) 518-5088) and (ii) to the Company at 321
Commonwealth Road, Wayland.

                                      -7-

<PAGE>

Massachusetts, 01778, Attention: Kevin Laracey, President (and/or if by
facsimile, (508) 647-6717) or at such other address as any such party may
subsequently designate by written notice to the other party with a copy to:
Testa, Hurwitz & Thibeault, LLP, High Street Tower, 125 High Street, Boston,
Massachusetts, Attention: William J. Schnoor, Jr., Esq.

    (f)  Remedies. In the event of any default hereunder, the non-defaulting
         --------
party may proceed to protect and enforce its rights either by suit in equity
and/or by action at law, including but not limited to an action for damages as a
result of any such default, and/or an action for specific performance for any
default where Warrantholder will not have an adequate remedy at law and where
damages will not be readily ascertainable. The Company expressly agrees that it
shall not oppose an application by the Warrantholder or any other person
entitled to the benefit of this Agreement requiring specific performance of any
or all provisions hereof or enjoining the Company from continuing to commit any
such breach of this Agreement.

    (g)  No Impairment of Rights. The Company will not, by amendment of its
         -----------------------
Charter or through any other means, avoid or seek to avoid the observance or
performance of any of the terms of this Warrant, but will at all times in good
faith assist in the carrying out of all such terms and in the taking of all such
actions as may be necessary or appropriate in order to protect the rights of the
Warrantholder against impairment.
<PAGE>

    (h)  Survival. The representations, warranties, covenants and conditions of
         --------
the respective parties contained herein or made pursuant to this Warrant
Agreement shall survive the execution and delivery of this Warrant Agreement.

    (i)  Severability. In the event any one or more of the provisions of this
         ------------
Warrant Agreement shall for any reason be held invalid, illegal or
unenforceable, the remaining provisions of this Warrant Agreement shall be
unimpaired, and the invalid, illegal or unenforceable provision shall be
replaced by a mutually acceptable valid, legal and enforceable provision, which
comes closest to the intention of the parties underlying the invalid, illegal or
unenforceable provision.

    (j)  Amendments. Any provision of this Warrant Agreement may be amended by a
         ----------
written instrument signed by the Company and the Warrantholder.

    (k)  Additional Documents. The Company, upon execution of this Warrant
         --------------------
Agreement, shall provide the Warrantholder with certified resolutions with
respect to the representations, warranties, and covenants set forth in
subparagraphs (a) through (d), (f) and (g) of Section 9 above.

    IN WITNESS WHEREOF, the parties hereto have caused this Warrant Agreement to
be executed by its officers thereunto duly authorized as of the Effective Date.

    Company:                    eDOCS, INC.

                                By: /s/ Kevin E. Laracey
                                    ------------------------
                                Title:   CEO
                                      ----------------------


    Warrantholder:              COMDISCO, INC.

                                By: /s/ James Labe
                                   -------------------------
                                Title:  President
                                        Comdisco Ventures Division


                                      -9-
<PAGE>

                                   EXHIBIT I

                              NOTICE OF EXERCISE


To:
      ---------------------------

(1)   The undersigned Warrantholder hereby elects to purchase shares of the
      Series A Convertible Preferred Stock of eDocs, Inc., pursuant to the terms
      of the Warrant Agreement dated the 31st day of March, 1999 (the "Warrant
      Agreement") between eDocs, Inc. and the Warrantholder, and tenders
      herewith payment of the purchase price for such shares in full, together
      with all applicable transfer taxes, if any.

(2)   In exercising its rights to purchase the Series A Convertible Preferred
      Stock of eDocs, Inc., the undersigned hereby confirms and acknowledges
      the investment representations and warranties made in Section 10 of the
      Warrant Agreement.

(3)   Please issue a certificate or certificates representing said shares of
      Series A Convertible Preferred Stock in the name of the undersigned or in
      such other name as is specified below.



------------------------------
(Name)

------------------------------
(Address)



Warrantholder: COMDISCO, INC.

By:
   --------------------------

Title:
      -----------------------

Date:
     ------------------------



                                     -10-
<PAGE>

                                  EXHIBIT II

                          ACKNOWLEDGMENT OF EXERCISE


    The undersigned__________________________________, hereby acknowledge
receipt of the "Notice of Exercise" from Comdisco, Inc., to purchase _____
shares of the Series A Convertible Preferred Stock of _____________________,
pursuant to the terms of the Warrant Agreement, and further acknowledges that
_______ shares remain subject to purchase under the terms of the Warrant
Agreement.

                                   Company: eDocs, Inc.


                                   By:
                                        --------------------

                                   Title:
                                          ------------------

                                   Date:
                                        --------------------



                                     -11-
<PAGE>

                                  EXHIBIT III

                                TRANSFER NOTICE

(To transfer or assign the foregoing Warrant Agreement, execute this form and
supply required information. Do not use this form to purchase shares.)

    FOR VALUE RECEIVED, the foregoing Warrant Agreement and all rights evidenced
thereby are hereby transferred and assigned to



-----------------------------------------------------
(Please Print)

whose address is ------------------------------------

-----------------------------------------------------

                     Dated:
                            -------------------------

                     Holder's Signature:
                                        -------------
                     Holder's Address:
                                      ---------------

                     --------------------------------

Signature Guaranteed:
                     --------------------------------


NOTE:   The signature to this Transfer Notice must correspond with the name as
        it appears on the face of the Warrant Agreement, without alteration or
        enlargement or any change whatever. Officers of corporations and those
        acting in a fiduciary or other representative capacity should file
        proper evidence of authority to assign the foregoing Warrant Agreement.



                                     -12-
<PAGE>

                                  EXHIBIT IV














                                     -13-