The USPS Electronic Postmark® (EPM)* is an auditable time-and-date stamp service offered by authorized service providers, under license by the United States Postal Service. The EPM can be used to verify the authenticity of a document or file sent electronically, and provides trusted proof of content as of a specific point in time.
EPMs issued by an authorized EPM service provider are stored in their repositories and available for verification for a period of up to seven years from the date of issuance. The USPS serves as the backup verifier for all EPMs issued by any of the following authorized providers of the USPS EPM service.
To purchase or learn more about EPM services, click on the authorized provider's link below.
![Authentidate Logo](https://webarchive.library.unt.edu/eot2008/20090508190244im_/https://www.usps.com/electronicpostmark/images/usps_epm_authentidate.gif)
![Get started with Electronic Postmark](https://webarchive.library.unt.edu/eot2008/20090508190244im_/https://www.usps.com/electronicpostmark/images/usps_epm_btn_getstarted.gif)
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![Image of keys](https://webarchive.library.unt.edu/eot2008/20090508190244im_/https://www.usps.com/electronicpostmark/images/usps_epm_keys.jpg) |