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                                                                   EXHIBIT 10.44

                 AMENDED AND RESTATED LOAN REPAYMENT AGREEMENT
                 ---------------------------------------------

     This Amended and Restated Loan Repayment Agreement ("Agreement"), is
entered into as of August 10, 2000, among Salomon Smith Barney Inc. ("SSB")
whose principal place of business is located at 388 Greenwich Street, New York,
NY 10013, Stamps.com Inc. ("Company"), whose principal place of business is
located at 3420 Ocean Park Boulevard, Suite 1040, Santa Monica, CA 90405, and
John Payne ("Payne"), who resides at 660 Thalia Street, Laguna Beach, CA 92651.

WHEREAS, SSB has previously extended credit to Payne in the amount of $10.2
million pursuant to the requirements of Federal Reserve Board Regulation T and
other applicable rules and regulations for margin accounts ("Margin Loan"), and
such Margin Loan is collateralized by the shares of the Company's common stock
("Stock"), as well as other property (and the proceeds thereof) contained in a
margin account maintained by Payne at SSB ("Margin Account"); and

WHEREAS, the parties previously had entered into that certain Loan Repayment
Agreement dated as of April 13, 2000 (the "Prior Agreement"), which agreement
shall be superseded in its entirety by this Agreement; and

WHEREAS, as of August 4, 2000, the Margin Account contained an outstanding debit
of $7,020,431.70 (the "Current Margin Amount"); and

WHEREAS, Payne is the Company's Chairman and Chief Executive Officer; and

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WHEREAS, At SSB's request, the Company has deposited ten million dollars into an
account at SSB in the Company's name ("Company Account") in order to provide SSB
with additional security for the repayment of the Margin Loan (including accrued
interest); and

WHEREAS, the parties wish to establish the obligations of the Company and Payne
with respect to the repayment of the Margin Loan;

NOW, THEREFORE, in consideration of the parties' covenants contained herein, and
intending to be legally bound by the terms and conditions of this Agreement, the
parties agree as follows:

1.)  The securities, cash, and other property contained in the Company Account,
and the proceeds of such property (collectively, "Property"), shall be owned
exclusively by the Company (and not by Payne) but may, under the circumstances
described in Sections 2 and 4 of this Agreement, be used to repay all or part of
the Margin Loan (including accrued interest, if any).  While the Margin Loan
remains outstanding, the Company may not withdraw any Property from the Company
Account, or substitute securities or other property for the Property, without
SSB's prior written consent.  The Property may be invested only in a money
market fund or overnight repurchase agreements relating to securities issued or
guaranteed by the U.S.

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2.)  a)  If at the close of trading on Nasdaq on any business day on which the
Margin Loan remains outstanding, the market value of the securities, cash and
other property contained in the Margin Account and the Company Account combined
falls below sixty (60) percent of the margin amount the Client is required by
applicable law or SSB policy to maintain (the "Margin Maintenance Level")
while the Margin Loan is outstanding, the Company shall on the next business
daydeposit a sufficient amount of additional Property in the Company Account to
restore the Margin Account and the Company Account combined to the Margin
Maintenance Level.

     b.)  In the event the closing price on Nasdaq of the Stock is equal to or
less than six (6) dollars per share in any three consecutive trading days, the
Company may in its sole discretion, upon commencement of trading on the next
business day and without prior notice to or demand upon Payne, direct SSB to
liquidate and sell any or all of the property in the Margin Account (including
the Stock) and apply the proceeds of such sale to the payment of the Margin
Loan. The only officers of the Company authorized to direct SSB to liquidate and
sell any or all of the property in the Margin Account (including the Stock)
shall be the Company's Chief Financial Officer, Controller or Secretary (each an
"Authorized Officer").

     c.)  Commencing with the third fiscal quarter of 2000 and until such time
as the Margin Loan is repaid in its entirety, Payne agrees to sell a minimum of
100,000 shares of Stock per fiscal quarter (the Company's fiscal year runs from
January 1 to December 31), the proceeds of which must be applied to the
repayment of the Margin Loan. The sale of the Stock must occur on or before the
last trading day of the second month of each fiscal quarter (the "Required Sale
Date"). In the event Payne does not direct the sale of the Stock prior to such
Required Sale Date, SSB shall automatically sell 100,000 shares of Stock on the
Required Sale Date without prior notice to or demand upon Payne and apply the
proceeds of such sale solely to the payment of the Margin Loan. Nothing in this
Section 2(c) shall impair SSB's right at any time while the Margin Loan is
outstanding to demand for any reason the immediate repayment of the Margin Loan
(including accrued interest) in whole or in part. In the event the Margin Loan
is not immediately repaid after a demand by SSB, SSB will be entitled as a
creditor under a loan in default to exercise the remedies described in Section
4(c) and to withdraw, liquidate or sell the stock and other property in the
Margin Account.

     d.)  SSB shall have no recourse to any assets of the Company other than the
Property in the Company Account in the event such proceeds (together with the
proceeds from the sale of securities, cash and other property in the Margin
Account) are not sufficient to repay the Margin Loan (including accrued
interest, if any) in full. Nothing herein shall prevent SSB from having full
recourse to all of

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Payne's personal assets to repay any unpaid amount of the Margin Loan (together
with accrued interest, if any, and all costs of collection).

       e.)  If at the close of trading on Nasdaq on any business day on which
the Margin Loan remains outstanding, the price per share of the Stock equals or
exceeds thirty (30) dollars, the Company shall be permitted to:

(i.)   withdraw from the Company Account up to (50) percent of the market value
of the Property and such withdrawn amount shall cease to be security for the
repayment of the Margin Loan; provided, however, that SSB may require the
Company (no later than the next business day) to deposit additional Property
into the Company Account in the event the market value of the securities, cash
and other property in the Margin Account, and the market value of the property
then remaining in the Company Account subsequently falls below the Margin
Maintenance Level. Notwithstanding the foregoing, the Company may not be
required to re-deposit into the Company Account an amount that exceeds its
previous withdrawal[s] from the Company Account; and

(ii.)  in its sole discretion, upon commencement of trading on the next business
day and without prior notice to or demand upon Payne, direct SSB to liquidate
and sell any or all of the property in the Margin Account (including the Stock)
and apply the proceeds of such sale to the payment of the Margin Loan. The only
officers of the Company authorized to direct SSB to liquidate and sell any or
all of the property in the Margin Account (including the Stock) shall be the
Authorized Officers.

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       f.)  Each party hereto agrees that the Margin Loan will solely consist of
the Current Margin Amount, plus any interest that has accrued or may accrue
thereon. Payne may not use any credit previously extended by SSB (except solely
for purposes of accruing interest on the Current Margin Amount), nor will SSB
extend Payne any additional credit, without the prior consent of the Board of
Directors of the Company.

3.)    Each party represents and warrants to the other two parties that it has
full authority to enter into this Agreement and to perform its obligations
hereunder. In addition, the Company represents and warrants to SSB that while
the Margin Loan is outstanding, (a) the Property in the Company Account is not
subject to any lien, encumbrance or impediment to transfer, (b) it will not
pledge or hypothecate the Property in the Company Account or grant a security
interest in such Property to a third party, or permit the Property to be sold,
transferred or become subject to any lien or encumbrance, and (c) in the event
SSB liquidates and sells any Property in the Company Account consisting of
securities, the Property will be readily transferable into "street name" in good
deliverable form.

4.)    a.)  Any of the following events will be considered a "default" by the
Company and/or Payne under this Agreement: (i) any representation or warranty
hereunder by the Company and/or Payne is incorrect in any material respect; (ii)
the Company fails to perform any of its obligations hereunder in any material
respect; (iii) the Company fails to comply with any applicable law, rule or
regulation that prevents it from performing its obligations hereunder in any
material respect; and (iv) a liquidator, receiver or trustee is appointed with
respect to all or

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substantially all of the assets of Payne and/or the Company, or a bankruptcy
petition is filed by or against Payne and/or the Company and in the case of a
petition filed against Payne and/or the Company, the petition is not dismissed
within sixty (60) business days after it is filed.

       b.)  In the event a default occurs, SSB is authorized, in its sole
discretion, to declare the Margin Loan to be immediately due and payable. In
addition, in the event of a default by the Company under Section 4(a)(iv), SSB
is authorized to liquidate, withdraw or sell the Property in the Company Account
and apply it to the Margin Loan without prior notice to, or demand upon SSB's
the Company or Payne. In addition, any sale may be made in SSB's sole discretion
on the exchange or market where such business is then usually transacted, at
public auction or private sale. All rights and remedies under this Agreement are
cumulative and are in addition to all other rights and remedies that SSB may
have at law or equity. Notwithstanding the foregoing and to the extent permitted
by law, the Company and Payne expressly waive compliance with the provisions of
Section 202 of the New York Lien Law.

5.)    None of the parties shall be liable to the other parties for (a) any loss
caused directly or indirectly by causes that are not within the party's
reasonable control, including government restrictions, exchange or market
rulings, suspension of trading, war, strikes or other conditions commonly known
as "Acts of God", or (b) any consequential, incidental, indirect or special
damages, even if such damages are reasonably foreseeable.

6.)    This Agreement shall be governed by, and construed in accordance with,
the laws of the State of New York, without regard to the conflict of laws rules
of such State.

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7.)  This Agreement may not be assigned by Payne or the Company without
SSB's written consent and shall be binding upon the heirs, executors,
administrators, successors and permitted assigns (whichever is applicable) of
the Company and/or Payne.  SSB may assign this Agreement without the other
parties' consent or prior notice to the other parties, to any of its affiliates
or subsidiaries that are authorized by law to make margin loans, and this
Agreement shall inure to the benefit of SSB's successors and assigns
(whether by merger, consolidation or otherwise).

8.)  a.)  Whenever the Margin Loan is repaid in full (including accrued
interest, if any), the Company may withdraw any Property remaining in the
Company Account that is not applied by SSB to such repayment.  This
Agreement will terminate upon the repayment of the Margin Loan and such
withdrawal of Property from the Company Account.

     b.)  This Agreement may be amended only in writing among the parties. If
any provision of this Agreement is held to be invalid, illegal or unenforceable
by reason of any law, rule, administrative order or judicial decision, such
determination shall not affect the validity of the remaining provisions of this
Agreement.

9.)  This Agreement (including all exhibits) reflects the entire agreement
between the parties concerning the subject matter of this Agreement and
supersedes any other agreement (including, but not limited to, the Agreement of
Guaranty and Cross Guaranty between the Company and SSB executed on April 13,
2000 and the Prior Agreement), promise, representation or undertaking, whether
written or oral, concerning the subject matter of this Agreement. In the event
of a conflict between the

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provisions of this Agreement and any other agreement among the parties, this
Agreement will govern.

10.)  Without the necessity of a judicial determination, and whether or not
litigation occurs, Payne and the Company hereby agree jointly and severally to
indemnify and hold harmless SSB and its directors, officers, employees,
agents and affiliates from any and all claims (whether or not meritorious),
liabilities, judgments, damages, losses, costs and expenses of any nature
whatsoever (including reasonable attorneys' fees and expenses) in any way
related to or arising out of or in connection with a.) the obligations of Payne
and the Company under this Agreement, and b.) the representations and warranties
of Payne and/or the Company in this Agreement.  This indemnification shall
survive the termination of this Agreement and the payment of the Margin Loan.

11.)  ARBITRATION

 .  Arbitration is final and binding on the parties.

 .  The parties are waiving their right to seek remedies in court, including the
   right to jury trial.

 .  Pre-arbitration discovery is generally more limited than and different from
   court proceedings.

 .  The arbitrators' award is not required to include factual findings or legal
   reasoning, and any party's rights to appeal or to seek modification of
   rulings by the arbitrators is strictly limited.

 .  The panel of arbitrators will typically include a minority of arbitrators who
   were or are affiliated with the securities industry.

The Company and Payne agree that all claims or controversies, whether such
claims or controversies arose prior, on or subsequent to the date hereof,
between the Company and Payne

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and SSB and/or any of its present or former officers, directors, or employees
concerning or arising from (i) the Margin Loan and any other transaction
involving SSB or any predecessor firms by merger, acquisition or other business
combination, whether or not such transaction occurred in the Margin or Company
Account, or (ii) the construction, performance or breach of this Agreement or
any other agreement between the Company, Payne and SSB, or any duty arising from
the business of SSB or otherwise, shall be determined by binding arbitration
before, and only before, any self-regulatory organization or exchange of which
SSB is a member. The Company and Payne may elect which of these arbitration
forums shall hear the matter by sending a registered letter or telegram
addressed to Salomon Smith Barney Inc. at 388 Greenwich Street, New York, NY
10013-2396, Attn: Law Department. If the Company and Payne fail to make such
election and agree upon a single forum before the expiration of five (5) days
after receipt of a written request from SSB to make such election, SSB shall
have the right to choose the forum.

No person shall bring a putative or certified class action to arbitration, nor
seek to enforce any pre-dispute arbitration agreement against any person who has
initiated in court a putative class action; or who is a member of a putative
class who has not opted out of the class with respect to any claims encompassed
by the putative class action until: (i) the class certification is denied, (ii)
the class is decertified, or (iii) the customer is excluded from the class by
the court.

Such forbearance to enforce an agreement to arbitrate shall not constitute a
waiver of any rights under this Agreement except to the extent stated herein.

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BY SIGNING BELOW, THE COMPANY AND PAYNE AGREE TO BE BOUND BY THE TERMS AND
CONDITIONS OF THIS AGREEMENT.  THIS AGREEMENT CONTAINS A PRE-DISPUTE ARBITRATION
CLAUSE AT SECTION 11.

/s/ John W. LaValle                        /s/ John Payne
------------------------------------       ------------------------------------
STAMPS.COM INC.                            JOHN PAYNE

By: John W. LaValle, EVP and CFO
    ---------------------------------------
[Print Name and Title of Authorized Official]

SALOMON SMITH BARNEY INC.

By: /s/ Salomon Smith Barney
    ---------------------------------------
[Print Name and Title of Authorized Official]

                                       10<PAGE>

                                                                   EXHIBIT 10.45

                                STAMPS.COM INC.
                                ---------------

               REVOLVING NOTE SECURED BY STOCK PLEDGE AGREEMENT
               ------------------------------------------------

$6,000,000                                                        April 12, 2000
                                                        Santa Monica, California

          FOR VALUE RECEIVED, John Payne ("Maker") promises to pay to the order
of Stamps.com Inc., a Delaware corporation (the "Corporation"), at its corporate
offices at 3420 Ocean Park Boulevard, Suite 1040, Santa Monica, California,
90405, the principal sum of SIX MILLION DOLLARS ($6,000,000) or such lesser
amount of Advances (as defined in Section 1 below) as may be outstanding from
time to time pursuant to the terms hereof, together with all accrued interest
thereon, upon the terms and conditions specified below.

          1.  Amount Due.  Pursuant to the Guarantee, by and between the
              ----------
Corporation and Salomon Smith Barney Inc. ("SSB"), the Corporation has agreed to
satisfy, on behalf of the Maker, any margin calls made by SSB to Maker by
establishing a cash collateral account (the "Account"). The amount of any such
margin call so satisfied by the Corporation shall be an "Advance" hereunder. To
the extent that SSB releases its security interest in the Account, Advances
hereunder shall no longer be outstanding and the principal amount previously
outstanding with respect to such Advances shall be deemed repaid.

          2.  Interest.  Interest shall accrue on the unpaid Advances
              --------
outstanding from time to time under this Note at the prime rate, compounded
semi-annually. Accrued and unpaid interest shall become due and payable on April
12, 2001, subject to the accelerated payment provisions of Paragraph 5 of this
Note; provided, however, that the Board of Directors of the Corporation may in
its sole discretion extend such date.

          3.  Principal.  The entire principal balance of this Note shall become
              ---------
due and payable in one lump sum on April 12, 2001, subject to the accelerated
payment provisions of Paragraphs 5 and 6 of this Note; provided, however, that
the Board of Directors of the Corporation may in its sole discretion extend such
date.

          4.  Payment.  Payment shall be made in lawful tender of the United
              -------
States and shall be applied first to the payment of all accrued and unpaid
interest and then to the payment of principal. Prepayment of the principal
balance of this Note, together with all accrued and unpaid interest on the
portion of principal so prepaid, may be made in whole or in part at any time
without penalty.

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          5.  Events of Acceleration.  The entire unpaid principal balance of
              ----------------------
this Note, together with all accrued and unpaid interest, shall become
immediately due and payable prior to the specified due date of this Note upon
the occurrence of one or more of the following events:

              A.  The failure of the Maker to pay any installment of accrued
     interest under this Note when due and the continuation of such default for
     more than thirty (30) days.

              B.  The expiration of the thirty (30)-day period following the
     date the Maker ceases for any reason to remain in the employ of the
     Corporation.

              C.  The insolvency of the Maker, the commission of any act of
     bankruptcy by the Maker, the execution by the Maker of a general assignment
     for the benefit of creditors, the filing by or against the Maker of any
     petition in bankruptcy or any petition for relief under the provisions of
     the Federal bankruptcy act or any other state or Federal law for the relief
     of debtors and the continuation of such petition without dismissal for a
     period of thirty (30) days or more, the appointment of a receiver or
     trustee to take possession of any property or assets of the Maker or the
     attachment of or execution against any property or assets of the Maker.

              D.  An acquisition of the Corporation (whether by merger, sale of
     all or substantially all of the Corporation's assets or sale of more than
     fifty percent (50%) of the Corporation's outstanding voting securities) for
     consideration payable in cash or freely-tradable securities; provided,
                                                                  --------
     however, that if the Pooling of Interest Method, as described in Accounting
     Principles Board Opinion No. 16, is used to account for the acquisition for
     financial accounting purposes, then acceleration of this Note shall not
     occur until the end of the sixty (60)-day period immediately following the
     close of the applicable transfer restriction period required under
     Accounting Series Release Numbers 130 and 135.

              E.  The occurrence of any event of default under the Stock Pledge
     Agreement securing this Note or any obligation secured thereby.

              F.  The Market Price (as defined below) of one share of the
     Corporation Common Stock on any three consecutive trading days is either
     below $6 or above $30.  "Market Price" as of any day shall mean:

                  (x)   If the Common Stock is at the time traded on the Nasdaq
              National Market, the fair market value shall be the closing
              selling price per share of Common Stock on the date in question,
              as such prices are reported by the National Association of
              Securities Dealers on the Nasdaq National Market. If there is no
              reported closing selling price for the Common Stock on the date in
              question, then the closing selling price on the last preceding
              date

                                       2.
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              for which such quotation exists shall be determinative of fair
              market value.

                  (y)   If the Common Stock is at the time listed on the
              American Stock Exchange or the New York Stock Exchange, then the
              fair market value shall be the closing selling price per share of
              Common Stock on the date in question on the securities exchange
              serving as the primary market for the Common Stock, as such price
              is officially quoted in the composite tape of transactions on such
              exchange. If there is no reported sale of Common Stock on such
              exchange on the date in question, then the fair market value shall
              be the closing selling price on the exchange on the last preceding
              date for which such quotation exists.

              G.  The shares of the Corporation's Common Stock cease to be
     listed on a national securities exchange or quoted on a Nasdaq Stock
     Market.

          6.  Employment.  The Maker shall be deemed to continue in employment
              ----------
with the Corporation for so long as he or she renders services as an employee of
the Corporation or one or more of the Corporation's fifty percent (50%) or more
owned (directly or indirectly) subsdiaries.

          7.  Security.  Payment of this Note shall be secured by a pledge of
              --------
1,467,000 shares of the Corporation's Common Stock ("Pledged Shares") with the
Corporation pursuant to the Stock Pledge Agreement to be executed as of the date
hereof by the Maker. Unless otherwise agreed among the Maker, SSB and the
Corporation, the Corporation's right to proceed against the Pledged Shares
pursuant to the Stock Pledge Agreement shall be subordinate to the right of
SSB to proceed against the Pledged Shares pursuant to the Pledge Agreement,
dated as of February 12, 2000, by and among the Maker and SSB. The Maker,
however, shall remain personally liable for payment of this Note, and any and
all assets of the Maker, in addition to the collateral under the Stock Pledge
Agreement, may be applied to the satisfaction of the Maker's obligations
hereunder.

          8.  Collection.  If action is instituted to collect this Note, the
              ----------
Maker promises to pay all costs and expenses (including reasonable attorney
fees) incurred in connection with such action.

          9.  Waiver.  A waiver of any term of this Note, the Stock Pledge
              ------
Agreement or of any of the obligations secured thereby must be made in writing
and signed by a duly-authorized officer of the Corporation and any such waiver
shall be limited to its express terms.

                                       3.
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          No delay by the Corporation in acting with respect to the terms of
this Note or the Stock Pledge Agreement shall constitute a waiver of any breach,
default, or failure of a condition under this Note, the Stock Pledge Agreement
or the obligations secured thereby.

          The Maker waives presentment, demand, notice of dishonor, notice of
default or delinquency, notice of acceleration, notice of protest and
nonpayment, notice of costs, expenses or losses and interest thereon, notice of
interest on interest and diligence in taking any action to collect any sums
owing under this Note or in proceeding against any of the rights or interests in
or to properties securing payment of this Note.

          10.  Conflicting Agreements.  In the event of any inconsistencies
               ----------------------
between the terms of this Note and the terms of any other document related to
the loan evidenced by the Note, the terms of this Note shall prevail.

          11.  Governing Law.  This Note shall be construed in accordance with
               -------------
the laws of the State of California without resort to that State's conflict-of-
laws rules.

                                                 /s/ John M. Payne
                                      ----------------------------------------
                                                MAKER: JOHN M. PAYNE

                                       4.

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