How do I add a custom return-path?

What is the Return-Path?

The Return-Path is the address where bounces and other email feedback are sent. It is specified by the Return-Path header in an email. The default Return-Path for emails sent through Postmark is:

Return-Path: <pm_bounces@pm.mtasv.net>

It is also described as:

  • bounce address
  • reverse path
  • envelope from
  • MAIL FROM

Why set a custom Return-Path?

A custom Return-Path isn't required and shouldn't affect deliverability in most cases but if you have a DMARC policy for your domain, you should set up a custom Return-Path to achieve SPF alignment.

If you send emails from example.com, then you can still pass SPF and DKIM authentication but since the Return-Path and From address are not using the same domain, SPF will not pass for DMARC alignment. When you set up a Return-Path domain of pmbounces.example.com and send emails from example.com then the domains will be aligned. When you send emails with a custom Return-Path, the header would look like:

Return-Path: <pm_bounces@pmbounces.example.com>

What is needed to set a custom Return-Path?

For your Return-Path domain, you need to create a CNAME record in DNS that points to pm.mtasv.net. This is so that Postmark is still able to collect bounces and other feedback sent to that address.

How to set a custom Return-Path in Postmark?

  1. Add a CNAME record to your DNS that points to pm.mtasv.net
  2. While logged into Postmark, select the Sender Signatures tab 
  3. Select the Authentication link on the domain you want to add the custom Return-Path domain on 
  4. Navigate to the heading Set up a custom Return-Path and enter in your alias you used in your CNAME record you added to your DNS

Still need help? Contact Us Contact Us