Return-path
MAIL FROM uses rp.your-domain when that CNAME verifies. Imported DKIM uses our zone until then.
The return-path is the envelope sender (MAIL FROM). Bounces and spam reports go to it. Publish the rp CNAME so that host is on your own domain.
How the return-path works
Every sending domain has a return-path host at rp.{name}, such as rp.mail.example.com. You publish it as a CNAME to the PostShiba return-path zone. The domain page shows the exact target. The CNAME can pass through a zone you control first, up to 8 hops.
return_path_status |
Envelope host | Can the domain send? |
|---|---|---|
verified |
rp.{name} |
Yes, once DKIM verifies |
| Not verified, default DKIM | Not used yet | No. Default DKIM needs the return-path first. |
| Not verified, Use my own DKIM key | The PostShiba return-path zone | Yes, once the DKIM TXT verifies |
Delivery status notifications and spam reports arrive at the return-path host. PostShiba matches them to the sending domain and stores the bounce or spam report on your team.
You cannot set Return-Path on a send
PostShiba owns MAIL FROM. A Return-Path value in the send API headers object is ignored. See Custom headers.
Publish the record
Publish the CNAME from the domain page, then select Check DNS. The steps are in Add and verify a domain.