What is the Sender Rewriting Scheme (SRS) in Email?

About

Sender Rewriting Scheme (SRS) is a process that rewrite the sender address:

[email protected]

into

[email protected]

It is mandatory in order to conform to the SPF scheme when the emails are forwarded.

With SRS, an MTA can circumvent SPF restrictions by replacing the envelope sender with a temporary email address from one of their own domains.

This temporary address is:

  • bound to the original sender
  • and only valid for a certain amount of time, which prevents abuse by spammers.

Example

If you get a forwarded email with SRS, you should see:

  • the email rewrite
  • the added Return Path
  • a successful SPF test

Example from Gmail

Postsrsd Spf Pass

Reference

https://www.libsrs2.org/srs/srs.pdf

Implementation





Discover More
Postsrsd Spf Pass
How to install the Sender Rewriting Scheme (SRS) on PostFix?

This page is the installation of postsrsd which implements Sender Rewriting Scheme (SRS) for Postfix. It's mandatory if you forward emails via the alias functionality....
What is email forwarding?

email forwarding happens when a MX SMTP server that manages the domain (for instance foo.com) transmits an email locally delivered (for instance to [email protected]) to another address that is not...



Share this page:
Follow us:
Task Runner