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:
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:
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?
- Add a CNAME record to your DNS that points to pm.mtasv.net
- While logged into Postmark, select the Sender Signatures tab
- Select the DNS Settings link on the domain you want to add the custom Return-Path domain on
- 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