MICROSOFT PARTNERS WITH STAMPS.COM TO BRING INTERNET POSTAGE TO MICROSOFT OFFICE USERS

Santa Monica, Calif., August 23, 1999 – Stamps.com (Nasdaq: STMP) today announced a partnership with Microsoft (Nasdaq: MSFT) that will offer the Stamps.com Internet Postage™ service through the popular Microsoft(R) Office Update Web site, (http://officeupdate.microsoft.com). The leader in the delivery of postage over the Internet, Stamps.com also announced today that its service will be available nationwide on September 27, 1999, launching in conjunction with national promotions to be held with key corporate partners.

As part of the Microsoft agreement, Stamps.com will make available to millions of Microsoft Office users its easy, convenient, secure and cost-effective Internet Postage service. Stamps.com allows customers to buy and apply postage using their PC and just an ordinary printer -requiring no hardware, no set-up fees, and no special connections. Customers can use Stamps.com in three simple steps: download the free software, register and print.

“This partnership is a major step forward in our company’s continued growth as the leader in the delivery of postage over the Internet,” said John Payne, president and CEO of Stamps.com. “Together with Microsoft, we will offer millions of Office users the fastest, simplest and most secure service for buying and printing postage from their printers.”

Stamps.com also integrates seamlessly with existing address books, word processors and other applications, including Microsoft Word and Outlook, so that customers can verify mailing addresses instantly and print postage directly from the software applications they currently use.

“Microsoft is excited to have Stamps.com provide our small office and home office customers online access to postage from within their Office applications,” said Taylor Collyer, Business Development Manager, Microsoft Corp. “With Office 2000, Microsoft has shown how the Internet can bring seamless integration of value-added services to the world’s premier productivity suite. The Stamps.com Internet Postage service is a great example of how Office 2000, a PC and the Internet combine to make people more productive,” added Collyer.

Stamps.com provides a convenient and cost-effective method for handling necessary administrative tasks. “With Internet Postage, sending mail finally seems to fit with the rest of the way I do business, and it integrates with the Microsoft products I use on a daily basis,” said Wellington Wilson, a Stamps.com customer.

Customers will be able to download the Stamps.com free software directly from the Microsoft Office Update download catalog and begin printing postage from their desktops within moments from signing up for the service. The Microsoft Office Update site is visited by millions of Office customers each month. With built-in links from Office products, it provides customers with free updates, add-on products and services that can add more value to their Office applications. With Office 2000, customers will have direct access from their desktop applications to the Microsoft Office Web site where they will be able to easily sign up for Stamps.com.

Stamps.com Availability

Stamps.com recently received U.S. Postal Service regulatory approval and is currently converting its beta customers to commercial service. Stamps.com service will be available to customers nationwide on September 27, 1999. Customers interested in using the service can go to the Stamps.com Web site, http://sdcmainprod.wpengine.com, to sign up.

About Stamps.com

Stamps.com (Nasdaq: STMP), founded in 1996, makes it easy for businesses and consumers to buy and print postage from their computers. The first and only Internet-based postage solution approved for commercial release, Stamps.com’s Internet Postage™ requires no additional hardware for users. The service is approved by the U.S. Postal Service under its Information Based Indicia Program (IBIP). Stamps.com partners include America Online, Inc. (AOL), Concentric Network Corp., Avery Dennison, MySoftware, Microsoft, Office Depot, Quicken.com, Westvaco, and other leading office supply and technology companies.

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Internet Postage™, Stamps.com and the Stamps.com logo are trademarks of Stamps.com Inc. All other brands and names are property of their respective owners.

“Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995: This release may contain forward-looking statements that involve risks and uncertainties. Important factors, which could cause actual results to differ materially from those in the forward-looking statements are detailed in filings with the Securities and Exchange Commission, made from time to time by Stamps.com, including its Form 10-Q for the quarter ended June 30, 1999, and Stamps.com’s prospectus, related to its initial public offering, that was filed with the SEC on June 25, 1999.