<PAGE>

                                                                     EXHIBIT 4.6

THESE SECURITIES HAVE BEEN ISSUED PURSUANT TO EXEMPTIONS FOR NONPUBLIC OFFERINGS
FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT OF 1933, AS AMENDED,
AND APPLICABLE STATE SECURITIES LAWS, AND, ACCORDINGLY, THESE SECURITIES MAY NOT
BE RESOLD OR OTHERWISE DISPOSED OF UNLESS, IN THE OPINION OF COUNSEL FOR OR
SATISFACTORY TO THE ISSUER, REGISTRATION UNDER THE APPLICABLE FEDERAL OR STATE
SECURITIES LAWS IS NOT REQUIRED OR COMPLIANCE IS MADE WITH SUCH REGISTRATION
REQUIREMENTS.

     Void after 5:00 p.m. New York Time, on October 22, 2004

               WARRANT TO PURCHASE 939,441 SHARES OF COMMON STOCK

                                       OF

                           OPEN PORT TECHNOLOGY, INC.

This is to certify that, FOR VALUE RECEIVED, Deutsche Bank Securities Inc. or
its registered assigns pursuant to Section (d) hereof ("Holder"), is entitled to
purchase, subject to the provisions of this Warrant, from Open Port Technology,
Inc., an Illinois corporation (the "Company"), 939,441 fully paid, validly
issued and nonassessable shares of Common Stock, par value $.001 per share, of
the Company ("Common Stock"), at the exercise price of $1.61 per share until
October 22, 2004.  The number of shares of Common Stock to be received upon the
exercise of this Warrant and the Exercise Price to be paid for each share of
Common Stock may be adjusted from time to time as hereinafter set forth.  The
shares of Common Stock deliverable upon such exercise, and as adjusted from time
to time, are hereinafter sometimes referred to as "Warrant Shares," and the
exercise price of a share of Common Stock as adjusted from time to time is
hereinafter sometimes referred to as the "Exercise Price."

     (a) EXERCISE OF WARRANT; NOTIFICATION OF EXPIRATION DATE OF WARRANT.  The
Warrant may be exercised as to a minimum of 100,000 Warrant Shares (as adjusted
for any stock dividends, combinations, splits, and the like with respect to the
Common Stock) at any time or from time to time, until 5:00 P.M. New York time on
October 22, 2004 (the "Expiration Date"), provided, however, that if such day is
a day on which banking institutions in the State of New York are authorized by
law to close, then on the next succeeding day which shall not be such a day.
The Warrant may be exercised by presentation and surrender hereof to the Company
at its principal office, or at the office of its stock transfer agent, if any,
with the Purchase Form annexed hereto duly executed (with signature guaranteed
if required by the Company or its stock transfer agent) and accompanied by
payment of the Exercise Price for the number of Warrant Shares specified in such
form and any applicable taxes.  The Exercise Price for any Warrant Shares
purchased pursuant to the exercise of this Warrant shall be paid in full upon
such exercise in cash or by certified or bank check or pursuant to a cashless
exercise procedure whereby the Warrant Shares issued upon exercise of this
Warrant will be sold by the
<PAGE>

Holder in compliance with all applicable federal and state securities laws, or
pursuant to applicable exemptions therefrom (such compliance or the availability
of such exemptions to be to the reasonable satisfaction of the Company) with
Holder receiving the difference between the Exercise Price and the sale price,
in cash, and the Company receiving the Exercise Price for the Warrant Shares, in
cash, or any combination of the foregoing methods of paying the Exercise Price.
In the alternative, the Warrant may be exchanged for Warrant Shares as described
in Section (l). As soon as practicable after each such exercise of the Warrants,
but not later than seven (7) business days from the date of such exercise, the
Company shall issue and deliver to the Holder a certificate or certificates for
the Warrant Shares issuable upon such exercise, registered in the name of the
Holder or the Holder's designee, except in the case of a cashless exercise. If
the Warrant should be exercised in part only, the Company shall, upon surrender
of the Warrant for cancellation, execute and deliver a new Warrant evidencing
the rights of the Holder thereof to purchase the balance of the Warrant Shares
purchasable thereunder. In the event of a cash exercise, upon receipt by the
Company of the Warrant at its office, or by the stock transfer agent of the
Company at its office, in proper form for exercise, together with the exercise
price thereof and taxes as aforesaid in cash or certified or bank check and the
investment letter described below, the Holder shall be deemed to be the holder
of record of the shares of Common Stock issuable upon such exercise,
notwithstanding that the stock transfer books of the Company shall then be
closed or that certificates representing such shares of Common Stock shall not
then be physically delivered to the Holder. In order to assure the availability
of an exemption from registration under the federal or applicable state
securities laws, the Company may condition the exercise of the Warrant upon the
Holder delivering to the Company an investment letter in the form as customarily
used by the Company from time to time in connection with the exercise of non-
registered options and warrants which are issued by the Company. It is further
understood that certificates for the Warrant Shares, if any, to be issued upon
exercise of the Warrant may contain a restrictive legend in accordance with
Section (j) hereof.

     (b) RESERVATION OF SHARES.  The Company shall at all times reserve for
issuance and/or delivery upon exercise of this Warrant such number of shares of
its Common Stock as shall be required for issuance and delivery upon exercise of
the Warrants. If the Common Stock is or becomes listed on any national
securities exchange or the NASDAQ National Market System, the Company shall also
notify such exchange or the NASDAQ system, as the case may be, of the issuance
of the Warrant Shares as required to maintain the listing of its Common Stock on
such exchange or the NASDAQ system, as the case may be.

     (c) FRACTIONAL SHARES.  No fractional shares or scrip representing
fractional shares shall be issued upon the exercise of the Warrant. With
respect to any fraction of a share called for upon any exercise hereof, the
Company shall pay to the Holder an amount in cash equal to such fraction
multiplied by the current market value of a share, determined as follows:

         (1) If the Common Stock is listed on a national securities exchange or
         admitted to unlisted trading privileges on such exchange or listed for
         trading on the NASDAQ National Market System, the current market value
         shall be the last reported sale

                                      -2-
<PAGE>

         price of the Common Stock on such exchange or system on the last
         business day prior to the date of exercise of this Warrant or if no
         such sale is made on such day, the average closing bid and asked prices
         for such day on such exchange or system;

         (2) If the Common Stock is not so listed or admitted to unlisted
         trading privileges, the current market value shall be the mean of the
         last reported bid and asked prices reported by the National Quotation
         Bureau, Inc., on the last business day prior to the date of the
         exercise of this Warrant; or

         (3) If the Common Stock is not so listed or admitted to unlisted
          trading privileges and bid and asked prices are not so reported, the
          current market value shall be an amount determined in such reasonable
          manner as may be prescribed by the Board of Directors of the Company.

     (d)  EXCHANGE, TRANSFER, ASSIGNMENT OR LOSS OF WARRANT. The Warrant is
exchangeable, without expense, at the option of the Holder, upon presentation
and surrender hereof to the Company or at the office of its stock transfer
agent, if any, for other Warrants of different denominations, but in increments
of not less than 100,000 Warrant Shares (as adjusted for any stock dividends,
combinations, splits, and the like with respect to the Common Stock), entitling
the Holder thereof to purchase in the aggregate the same number of shares of
Common Stock purchasable hereunder. Subject to Section (j) hereof, the Holder
may transfer or assign the Warrant, in whole or in part and from time to time;
provided that, at all times prior to an IPO, the Holder may only transfer or
assign the Warrant or the Warrant Shares to an affiliate of the Holder. Upon
surrender of this Warrant to the Company at its principal office or at the
office of its stock transfer agent, if any, with the Assignment Form annexed
hereto duly executed (with signature guaranteed, if required by the Company or
its stock transfer agent) and funds sufficient to pay any transfer tax, the
Company shall, without charge, execute and deliver a new Warrant in the name of
the assignee or assignees named in such instrument of assignment and this
Warrant shall promptly be canceled.  This Warrant may be divided by or combined
with other Warrants which carry the same rights upon presentation hereof at the
principal office of the Company or at the office of its stock transfer agent, if
any, together with a written notice specifying the names and denominations in
which new Warrants are to be issued and signed by the Holder hereof.  The term
"Warrant" as used herein includes any Warrants into which this Warrant my be
divided or exchanged.  Upon receipt by the Company of evidence satisfactory to
it of the loss, theft, destruction or mutilation of this Warrant, and in the
case of loss, theft or destruction, of reasonable satisfactory indemnification,
and upon surrender and cancellation of this Warrant, if mutilated, the Company
will execute and deliver a new Warrant of like tenor, date and amount. Any such
new Warrant executed and delivered shall constitute an additional contractual
obligation on the part of the Company, whether or not the original Warrant shall
be at any time enforceable by anyone.

     (e)  RIGHTS OF THE HOLDER.  The Holder shall not, by virtue hereof, be
entitled to any rights of a shareholder in the Company, either at law or equity,
and the rights of the Holder

                                      -3-
<PAGE>

are limited to those expressed in the Warrant and are not enforceable against
the Company except to the extent set forth herein.

     (f)  ANTI-DILUTION PROVISIONS.  So long as this Warrant shall be
outstanding, the Exercise Price in effect at any time and the number and kind of
securities purchasable upon the exercise of the Warrants shall be subject to
adjustment from time to time upon the happening of certain events as follows:

             (1) In case the Company shall (i) declare a dividend or make a
                 distribution on its outstanding shares of Common Stock in
                 shares of Common Stock, (ii) subdivide or reclassify its
                 outstanding shares of Common Stock into a greater number of
                 shares, or (iii) combine or reclassify its outstanding shares
                 of Common Stock into a smaller number of shares, the Exercise
                 Price in effect at the time of the record date for such
                 dividend or distribution, or the effective date of such
                 subdivision, combination or reclassification shall be
                 proportionately adjusted as of the effective date of such event
                 by multiplying such Exercise Price by a fraction, the
                 denominator of which shall be the number of shares of Common
                 Stock outstanding immediately following such event and the
                 numerator of which shall be the number of shares of Common
                 Stock outstanding immediately prior thereto. For example, if
                 the Company declares a 2 for 1 stock distribution and the
                 Exercise Price immediately prior to such event was $1.00 per
                 share, the adjusted Exercise Price immediately after such event
                 would be $.50 per share. Such adjustment shall be made
                 successively whenever any event listed above shall occur.

             (2) The Exercise Price in effect from time to time shall be also
                 adjusted to reflect any and all adjustments to the "Series E
                 Conversion Price" (as defined in the Amended and Restated
                 Articles of Incorporation of the Company (the "Articles")) as
                 calculated pursuant to subsection 4(e) of Part A of Paragraph 2
                 of Article 4 of the Articles. At any such time as all of the
                 Series E Convertible Participating Preferred Stock of the
                 Company (the "Series E Preferred Stock") is converted into
                 Common Stock, no further adjustments pursuant to this
                 subsection (2) shall be made. Any adjustments pursuant to
                 subsection (1) immediately preceding shall be taken into
                 account in making adjustments pursuant to this subsection. By
                 way of example, if the Series E Conversion Price is reduced to
                 $1.51, the Exercise Price shall be similarly reduced, but if
                 the adjustment to the Series E Conversion Price followed a 2
                 for 1 stock distribution, the resulting Exercise Price would be
                 $.755 per share.

             (3) Whenever the Exercise Price payable upon exercise of each
                 Warrant is adjusted pursuant to subsection (1) or (2) above,
                 the number of Warrant Shares purchasable upon exercise of the
                 Warrant shall simultaneously be adjusted by multiplying the
                 number of Warrant Shares issuable upon exercise


                                      -4-
<PAGE>

                 of this Warrant by the Exercise Price in effect on the date
                 hereof and dividing the product so obtained by the Exercise
                 Price, as adjusted pursuant to subsection (1) or (2), as
                 appropriate.

             (4) No adjustment in the Exercise Price shall be required unless
                 such adjustment would require an increase or decrease of at
                 least $.05 in such price; provided, however, that any
                 adjustments which by reason of this subsection (f) (3) are not
                 required to be made shall be carried forward and taken into
                 account in any subsequent adjustment required to be made
                 hereunder.

             (5) Each computation required by this Section (f) for purposes of
                 determining whether the Exercise Price shall be adjusted, shall
                 be performed by the Company. Whenever the Exercise Price is
                 adjusted, as herein provided, the Company shall promptly cause
                 a notice setting forth the adjusted Exercise Price and adjusted
                 number of Warrant Shares issuable upon exercise of each Warrant
                 to be mailed to the Holder, at its address appearing in the
                 Warrant Register, and shall cause a certified copy thereof to
                 be mailed to its transfer agent, if any.

             (6) All calculations under this Section (f) shall be made to the
                 nearest cent or to the nearest Warrant Share, as the case may
                 be.

             (7) In the event that at any time, as a result of an adjustment
                 made pursuant to this Section (f) above, the Holder of this
                 Warrant thereafter shall become entitled to receive any shares
                 of the Company, other than Common Stock, thereafter the number
                 of such other shares so receivable upon exercise of this
                 Warrant shall be subject to adjustment from time to time in a
                 manner and on terms as nearly equivalent as practicable to the
                 provisions with respect to the Common Stock contained in
                 subsection (a) above.

             (8) Irrespective of any adjustments in the Exercise Price or the
                 number or kind of Warrant Shares purchasable upon exercise of
                 this Warrant, Warrants theretofore or thereafter issued may
                 continue to express the same price and number and kind of
                 shares as are stated in the similar Warrants initially issuable
                 pursuant to this Agreement.

          (g) OFFICER'S CERTIFICATE.  Whenever the Exercise Price shall be
adjusted as required by the provisions of the foregoing Section, the Company
shall forthwith file in the custody of its Secretary or an Assistant Secretary
at its principal office and with its stock transfer agent, if any, an officer's
certificate showing the adjusted Exercise Price determined as herein provided,
setting forth in reasonable detail the facts requiring such adjustment,
including a statement of the number of additional shares of Common Stock, if
any, and such other facts as shall be necessary to show the reason for and the
manner of computing such adjustment. Each

                                      -5-
<PAGE>

such officer's certificate shall be made available at all reasonable times for
inspection by the Holder or any holder of a Warrant executed and/or delivered
pursuant to Section (a) or Section (d), and the Company shall, forthwith after
each such adjustment, mail, by certified mail, a copy of such certificate to the
Holder or any such holder.

          (h) NOTICES TO WARRANT HOLDERS.  So long as this Warrant shall be
outstanding, (i) if the Company shall pay any dividend or make any distribution
upon the Common Stock, or (ii) if the Company shall offer to the holders of
Common Stock for subscription or purchase by them any shares of any class or any
other rights, or (iii) if any capital reorganization of the Company,
reclassification of the capital stock of the Company, consolidation or merger of
the Company with or into another corporation, sale, lease or transfer of all or
substantially all of the property and assets of the Company to another
corporation, or voluntary or involuntary dissolution, liquidation or winding up
of the Company shall be effected, then in any such case, the Company shall cause
to be mailed by certified mail to the Holder or any holder of a Warrant executed
and/or delivered pursuant to Section (a) or Section (d), at least 15 days prior
to the date specified in (x) or (y) below, as the case may be, a notice
containing a brief description of the proposed action and stating the date on
which (x) a record is to be taken for the purpose of such dividend, distribution
or rights, or (y) such reclassification, reorganization, consolidation, merger,
conveyance, lease, dissolution, liquidation or winding up is to take place and
the date, if any is to be fixed, as of which the holders of Common Stock or
other securities shall receive cash or other property deliverable upon such
reclassification, reorganization, consolidation, merger, conveyance,
dissolution, liquidation or winding up.

          (i) RECLASSIFICATION OR REORGANIZATION. In case of any
reclassification or capital reorganization of outstanding shares of Common Stock
of the Company, or in case of any consolidation or merger of the Company with or
into another corporation (other than a merger with another corporation in which
merger the Company is the continuing corporation and which does not result in
any reclassification or capital reorganization of outstanding shares of Common
Stock of the class issuable upon exercise of this Warrant) or in case of any
sale, lease or conveyance to another corporation of the property of the Company
as an entirety, the Company shall, as a condition precedent to such transaction,
cause effective provisions to be made so that the Holder or any holder of a
Warrant executed and/or delivered pursuant to Section (a) or Section (d) shall
have the right thereafter by exercising the Warrant at any time prior to the
expiration of the Warrant, to purchase the kind and amount of shares of stock
and other securities and property receivable upon such reclassification or
capital reorganization and consolidation, merger, sale or conveyance.  Any such
provision shall include provision for adjustments which shall be as nearly
equivalent as may be practicable to the adjustments provided for in the Warrant.
The foregoing provisions of this Section (i) shall similarly apply to successive
reclassifications or capital reorganizations of shares of Common Stock and to
successive consolidations, mergers, sales or conveyances.  In the event that in
connection with any such capital reorganization or reclassification,
consolidation, merger, sale or conveyance, additional shares of Common Stock
shall be issued in exchange, conversion, substitution or payment, in whole or in
part, for a security of the Company other than Common Stock, any such issue
shall

                                      -6-
<PAGE>

be treated as an issue of Common Stock covered by the provisions of subsection
(1) of Section (f) hereof.

             (j)  SECURITIES LAW COMPLIANCE

                    (1) The Holder of the Warrant, by acceptance hereof,
                    acknowledges that (i) THE WARRANT AND THE WARRANT SHARES
                    HAVE BEEN, OR WILL BE, AS APPLICABLE, ISSUED PURSUANT TO
                    EXEMPTIONS FOR NONPUBLIC OFFERINGS FROM THE REGISTRATION
                    REQUIREMENTS OF THE SECURITIES ACT OF 1933, AS AMENDED, AND
                    APPLICABLE STATE SECURITIES LAWS, AND, ACCORDINGLY, THESE
                    SECURITIES MAY NOT BE RESOLD OR OTHERWISE DISPOSED OF
                    UNLESS, IN THE OPINION OF COUNSEL FOR OR SATISFACTORY TO THE
                    ISSUER, REGISTRATION UNDER THE APPLICABLE FEDERAL OR STATE
                    SECURITIES LAWS IS NOT REQUIRED OR COMPLIANCE IS MADE WITH
                    SUCH REGISTRATION REQUIREMENTS; and (ii) the Warrant and the
                    Warrant Shares to be issued upon exercise hereof or
                    conversion thereof are being acquired solely for the
                    Holder's own account and not as a nominee for any other
                    party, and for investment, and that the Holder will not
                    offer, sell, transfer, assign or otherwise dispose of this
                    Warrant or any shares of Common Stock to be issued upon
                    exercise hereof or conversion thereof except under
                    circumstances that will not result in a violation of the
                    Securities Act of 1933, as amended (the "Act") or any state
                    securities laws. Upon exercise or other transfer of the
                    Warrant, the Holder shall, if requested by the Company,
                    confirm in writing, in a form satisfactory to the Company,
                    that the shares of Common Stock so purchased or transferred
                    are being acquired solely for the Holder's own account and
                    not as a nominee for any other party, for investment, and
                    not with a view toward distribution or resale.

                    (2) If appropriate, the Warrant and any Warrants issued upon
                    exercise or substitution or upon assignment or transfer
                    pursuant to Section (a) or Section (d), as the case may be,
                    and all shares of Common Stock issued upon exercise hereof
                    or conversion thereof shall be stamped or imprinted with
                    legends setting forth the restrictions on transfer arising
                    under applicable federal and state securities laws.


             (k) REGISTRATION RIGHTS UNDER THE SECURITIES ACT OF 1933

                    (1) Commencing the date hereof and continuing until the
                    earlier of (i) sale or disposition of the securities covered
                    hereunder in accordance with any registration statement
                    ("Registration Statement") filed pursuant to the Securities
                    Act of 1933, as amended (the "Act"), or (ii) the Holder may
                    sell or transfer the Warrant or Warrant Shares in accordance
                    with the requirements of Section (k) (or similar

                                      -7-
<PAGE>

          provisions then in effect) of Rule 144 promulgated by the Securities
          and Exchange Commission under the Act, the Company shall advise the
          Holder of the Warrant or of the Warrant Shares or any then Holder of
          Warrants or Warrant Shares (such persons being collectively referred
          to herein as "Holders") by written notice (a "Registration Notice") at
          least 21 days prior to the filing of any Registration Statement or
          post-effective amendment thereto under the Act, covering an
          underwritten public offering of equity securities of the Company and
          shall register in any such Registration Statement the number of
          Warrant Shares that the Holder shall notify the Company within 10 days
          of such Holder's receipt of the Registration Notice that it desires to
          register and shall include in any such Registration Statement such
          information as may be required to permit a public offering of such
          Warrant Shares by the Company's underwriter(s). The Company shall
          supply prospectuses and other documents as the Holder may reasonably
          request in order to facilitate the public sale or other disposition of
          the Warrant Shares. The Company shall bear the entire cost and expense
          of a registration of securities initiated by it under this Paragraph
          (1). The Holder shall, however, bear the fees of its own counsel and
          any transfer taxes and underwriting discounts or commissions
          applicable to the Warrant Shares sold by it. The Company may include
          other securities in any such Registration Statement. The Company shall
          do any and all other acts and things which may be reasonably necessary
          or desirable to enable the Holder to consummate the public sale or
          other disposition of the Warrant Shares, and furnish indemnification
          in the manner as set forth in Paragraph (2) (a) of this Section (k),
          but shall not be required to qualify as a foreign corporation to
          qualify the Warrant Shares for sale under the securities laws of any
          state. The Holder shall furnish information and indemnification as set
          forth in Paragraph (2) (b) of this Section (k). All Holders whose
          securities are included in the public sale must sell their securities
          on the same terms and conditions as apply to the securities being
          issued and sold by the Company. All decisions as to whether and when
          to proceed with any Registration Statement shall be made solely by the
          Company, and the Company may delay or terminate any offering.

              Notwithstanding the foregoing paragraph, in the event that there
          is an underwritten offering of the Company's securities offered
          pursuant to said Registration Statement pursuant to the immediately
          preceding Paragraph, the underwriter(s) shall have the right to refuse
          to permit any Warrant Shares, or to limit the amount of Warrant
          Shares, to be sold by the Holder to such underwriter(s) as such
          underwriter(s) may determine in its discretion, and the Holder shall
          refrain from selling such remainder of its Warrant Shares covered by
          such registration statement for the period of 180 days following the
          effective date and shall also refrain at any time when notified by the
          Company that an amendment or supplement to the prospectus is required.
          The Company shall not be obligated to keep any Registration Statement
          effective for a total of more than 180 days.

                                      -8-
<PAGE>

          (2) (a)  Whenever pursuant to this Section (k) a Registration
          Statement relating to the Warrant Shares is filed under the Act,
          amended or supplemented, the Company will indemnify and hold harmless
          each Holder of Warrant Shares covered by such Registration Statement,
          amendment or supplement (such Holder being hereinafter called the
          "Distributing Holder"), and each person, if any who controls (within
          the meaning of the Act) the Distributing Holder, against any losses,
          claims, damages or liabilities, joint or several, to which the
          Distributing Holder or any such controlling person may become subject,
          under the Act or otherwise, insofar as such losses, claims, damages or
          liabilities (or actions in respect thereof) arise out of or are based
          upon any untrue statement or alleged untrue statement of any material
          fact contained in any such Registration Statement or any preliminary
          prospectus or final prospectus constituting a part thereof or any
          amendment or supplement thereto, or arise out of or are based upon the
          omission to state therein a material fact required to be stated
          therein or necessary to make the statements therein not misleading;
          and will reimburse the Distributing Holder and each such controlling
          person for any legal or other expenses reasonably incurred by the
          Distributing Holder and each controlling person for any legal or other
          expenses reasonable incurred by the Distributing Holder or such
          controlling person or underwriter in connection with investigating or
          defending any such loss, claim, damage, liability or action; provided,
          however, that the Company will not be liable in any such case to the
          extent that any such loss, claim, damage or liability arises out of or
          is based upon an untrue statement or alleged untrue statement or
          omission or alleged omission made in said Registration Statement,
          preliminary prospectus, final prospectus or amendment or supplement,
          in reliance upon and in conformity with written information furnished
          by the Distributing Holder or underwriter for use in the preparation
          thereof.

          (b)  The Distributing Holder will indemnify and hold harmless the
          Company, each of its directors, each of its officers who have signed
          said Registration Statement and such amendments and supplements
          thereto, each person, if any, who controls the Company (within the
          meaning of the Act) and the Company's underwriter(s) and each person,
          if any, who controls such underwriter(s) (within the meaning of the
          Act) against any losses, claims, damages or liabilities to which the
          Company or any such director, officer, underwriter or controlling
          person may become subject, under the Act or otherwise, insofar as such
          losses, claims, damages or liabilities arise out of or are based upon
          any untrue or alleged untrue statement of any material fact contained
          in said Registration

                                      -9-
<PAGE>

          Statement, preliminary prospectus, final prospectus, or amendment or
          supplement, or arise out of or are based upon the omission or the
          alleged omission to state therein a material fact required to be
          stated therein or necessary to make the statements therein not
          misleading, in each case to the extent, but only to the extent that
          such untrue statement or alleged untrue statement or omission or
          alleged omission was made in said Registration Statement, preliminary
          prospectus, final prospectus or amendment or supplement, in reliance
          upon and in conformity with written information furnished by such
          Distributing Holder for use in the preparation thereof; and will
          reimburse the Company or underwriter or any such director, officer or
          controlling person for any legal or other expenses reasonably incurred
          by them in connection with investigating or defending any such loss,
          claim, damage, liability or action.

          (c)  Promptly after receipt by an indemnified party under this
          Paragraph 2 of notice of the commencement of any action, such
          indemnified party will, if a claim in respect thereof is to be made
          against any indemnifying party, give the indemnifying party notice of
          the commencement thereof; but the omission so to notify the
          indemnifying party will not relieve it from any liability which it may
          have to any indemnified party otherwise than under this Paragraph 2.

          (d)  In case any such action is brought against any indemnified party,
          and it notifies an indemnifying party of the commencement thereof, the
          indemnifying party will be entitled to participate in, and, the extent
          that it may wish, jointly with any other indemnifying party similarly
          notified to assume the defense thereof, with counsel reasonably
          satisfactory to such indemnified party, and after notice from the
          indemnifying party to such indemnified party of its election so to
          assume the defense thereof, the indemnifying party will not be liable
          to such indemnified party under this Paragraph 2 for any legal or
          other expenses subsequently incurred by such indemnified party in
          connection with the defense thereof other than reasonable costs of
          investigation.

          (e)  The Company's agreements with respect to Warrant Shares in this
          Section (k) shall continue in effect regardless of the exercise or
          surrender of the Warrant.

     (l)  RIGHT TO CONVERT WARRANT INTO COMMON STOCK.

          (1)  Right to Convert.  The Holder shall have the right to require the
               ----------------
          Company to convert this Warrant provided in this Section (1), into
          common stock (the "Net Conversion Right").  Upon exercise of the Net
          Conversion Right, the Company shall deliver to the Holder (without
          payment by the Holder of any Exercise Price or of any other cash or
          consideration) that number of shares of Common Stock equal to the
          quotient obtained by dividing (x) the value of this Warrant at the
          time the Conversion Right is exercised (determined by subtracting the
          aggregate Exercise Price in effect immediately prior to the exercise
          of the Conversion Right from the aggregate fair market value of the
          shares of Common Stock issuable upon exercise of this Warrant
          immediately prior to the exercise of the Conversion Right) by (y) the
          fair market value of one share of Common Stock immediately prior to
          the exercise of the Conversion Right.

                                      -10-
<PAGE>

          (2)  Method of Exercise.  The Net Conversion Right may be exercised by
               ------------------
          the Holder by the surrender of this Warrant at the principal office of
          the Company together with a written statement specifying that the
          Holder thereby intends to exercise the Net Conversion Right.
          Certificates for the shares of Common Stock issuable upon exercise of
          the Net Conversion Right shall be delivered to the Holder within five
          (5) days following the Company's receipt of this Warrant together with
          the aforesaid written statement.

          (3)  Determination of Fair Market Value.  For purposes of this Section
               ----------------------------------
          (f), fair market value of a share of Common Stock as of a particular
          date (the "Determination Date") shall be determined in accordance with
          Section (c) of this Warrant.

     (m)  AMENDMENTS.  Neither the Warrant nor any term hereof may be
changed, waived, discharged or terminated without the prior written consent of
the Holder.

     (n)  NO IMPAIRMENT.  The Company will not avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed
hereunder by the Company, but will at all times in good faith assist in the
carrying out of all the provisions of this Warrant and in the taking of all such
action as may be necessary or appropriate in order to protect the rights of any
Holder.

     (o)  GOVERNING LAW.  This Agreement shall be governed by and
construed under the laws of the State of Delaware.

     (p)  NOTICES.  All notices and other communications required or
permitted hereunder shall be in writing and shall be mailed by first class mail,
postage prepaid, addressed (a) if to the Holder, to Deutsche Bank Securities
Inc., 1 South Street, Baltimore, Maryland 21202, Attention:  President, or (b)
if to the Company, to 676 North St. Clair Street, Suite 900, Chicago, Illinois
60611, Attention: Chief Executive Officer, or at such other address as to the
Company shall have furnished to the Holder in writing.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                                      -11-
<PAGE>

          IN WITNESS WHEREOF, Open Port Technology, Inc. has caused this Warrant
to be executed by its officer thereunto duly authorized.

Dated:  October 22, 1999

                                    OPEN PORT TECHNOLOGY, INC.


                                    By:/s/ Randy S. Storch
                                       ____________________________
                                    Name: Randy S. Storch
                                          _________________________
                                    Title: Chief Executive Officer
                                           ________________________

<PAGE>

                                 PURCHASE FORM
                                 -------------


                                    Dated _______________, _____


          [The undersigned hereby irrevocably elects to exercise its rights
pursuant to this Warrant to the extent of purchasing ______ shares of Common
Stock of Open Port Technology, Inc., and hereby makes payment of $___________,
in cash, in payment of the exercise price thereof.]

          The undersigned hereby irrevocably elects to exercise its rights
pursuant to this Warrant to the extent of purchasing _____ shares of Common
Stock and hereby authorizes you to deliver such shares of Common Stock for sale
to ___________, and to retain from the proceeds of such sale $__________, in
cash, in payment of the exercise price thereof and to remit to the undersigned
the balance of such proceeds.


                               _________________


                     INSTRUCTIONS FOR REGISTRATION OF STOCK
                     --------------------------------------


Name___________________________________________________________________________
                 (Please typewrite or print in block letters)


Address________________________________________________________________________

Signature______________________________________________________________________

<PAGE>

                                ASSIGNMENT FORM
                                ---------------


FOR VALUE RECEIVED,____________________________________________________________
hereby sells, assigns and transfers unto


Name___________________________________________________________________________
                  (Please typewrite or print in block letters)

Address________________________________________________________________________

the right to purchase Common Stock of Open Port Technology, Inc. (the
"Company"), represented by this Warrant to the extent of __________ shares as to
which such right is exercisable and does hereby irrevocably constitute and
appoint _____________________________ as Attorney, to transfer the same on the
books of the Company with full power of substitution in the premises.


Date ___________, _____

Signature__________________________