Tracking bounced messages with VERP

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Some mailing list programs, such as Mailman or Dada Mail, can be configured to track messages they send out and which then get bounced by using a special method called VERP. You can also use this method to track bounced messages and then manually unsubscribe the associated person from your mailing list.

VERP encodes each user's destination email address into a custom return path address. For example, if you normally send messages with a return path of, and you want to send a message to, then using normal protocols (ie, without using the special VERP method), your email would be sent like this:


Any such message that bounces would be sent back to the return path address (

However, a message sent using VERP would look like this (only the Return-Path is different):


Any VERP message which bounces would get returned to the address. Our mail server will silently ignore everything between the "+" and the "@", and will deliver the bounce notification to

You can then handle the bounce notification in several ways:

  • You can read them manually and unsubscribe the appropriate person.
  • Mailman will automatically read these bounce messages and unsubscribe the associated user.
  • Dada Mail can be configured to automatically pick up such bounces and unsubscribe people, but it takes more effort; please see the Dada Mail documentation for full details.

Note: In order for VERP to work, you need to make sure that you send messages using a "+" separator instead of the default "-" separator. If you are using Dada Mail, be sure to edit your Dada Mail configuration file.

Note: If you are running a mailing list, please be sure to review our mailing list policy.