EXHIBIT 99.4

                   FORM OF ADDENDUM TO STOCK OPTION AGREEMENT
 (Involuntary Termination Following Corporation Transaction/Change in Control)



                                    ADDENDUM
                                       TO
                             STOCK OPTION AGREEMENT

            The following provisions are hereby incorporated into, and are
hereby made a part of, that certain Stock Option Agreement (the "Option
Agreement") by and between Juno Online Services, Inc. (the "Corporation") and
___________________ ("Optionee") evidencing the stock option (the "Option")
granted on ___________, 199__ to Optionee under the terms of the Corporation's
1999 Stock Incentive Plan, and such provisions shall be effective immediately.
All capitalized terms in this Addendum, to the extent not otherwise defined
herein, shall have the meanings assigned to them in the Option Agreement.

                             INVOLUNTARY TERMINATION
                           FOLLOWING CHANGE IN CONTROL

            1. To the extent the Option does not accelerate, in connection with
a Change in Control, the Option shall continue, over Optionee's period of
Service after the Change in Control, to become exercisable for the Option Shares
in one or more installments in accordance with the provisions of the Option
Agreement. However, immediately upon an Involuntary Termination of Optionee's
Service within eighteen (18) months following such Change in Control, the Option
(or any replacement grant), to the extent outstanding at the time but not
otherwise fully exercisable, shall automatically accelerate so that the Option
shall become immediately exercisable for all the Option Shares at the time
subject to the Option and may be exercised for any or all of those shares as
fully vested shares of Common Stock.

            2. The Option as accelerated under Paragraph 1 shall remain so
exercisable until the earlier of (i) the Expiration Date or (ii) the expiration
of the one (1)-year period measured from the effective date of Optionee's
Involuntary Termination.

            3. For purposes of this Addendum, an Involuntary Termination shall
mean the termination of Optionee's Service by reason of:

                        (A) Optionee's involuntary dismissal or discharge by the
            Corporation for reasons other than Misconduct, or

                        (B) Optionee's voluntary resignation following (A) a
            change in Optionee's position with the Corporation (or Parent or
            Subsidiary employing Optionee) which materially reduces Optionee's
            level of responsibility, (B) a reduction in Optionee's level of
            compensation (including base salary, fringe benefits and target
            bonus under any corporate-performance based bonus or incentive
            programs) by more than fifteen percent (15%) or (C) a relocation of
            Optionee's place of employment by more than fifty (50) miles,
            provided and only if such change, reduction or relocation is
            effected by the Corporation without Optionee's consent.



            4. The provisions of Paragraph 2 of this Addendum shall govern the
period for which the Option is to remain exercisable following the Involuntary
Termination of Optionee's Service within eighteen (18) months after the Change
in Control and shall supersede any provisions to the contrary in Paragraph 5 of
the Option Agreement.


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