Setup guide
Postmark: SPF, DKIM and DMARC
Postmark needs a DKIM TXT record with a date-based selector and a Return-Path CNAME. No change to your root SPF record is needed.
DNS records to add
TXTHost
<date>pm._domainkey<DKIM value from Postmark → Sender Signatures → DNS Settings>Get this value from your provider's dashboard.DKIM signing key
CNAMEHost
pm-bouncespm.mtasv.netCustom Return-Path so SPF aligns
Steps
- In Postmark open Sender Signatures → your domain → DNS Settings.
- Publish the DKIM TXT record exactly as shown; the selector contains a timestamp.
- Publish the pm-bounces CNAME and click Verify for both records.
Good to know
- Our DKIM check can't guess Postmark's selector. Enter it (for example 20240212123456pm) to check the key.
Adding records at your DNS host
Cloudflare · Namecheap · GoDaddy · Amazon Route 53
Check your setup
After publishing, run the domain health check. DNS changes usually appear within minutes, but can take up to a few hours. Official reference: Postmark documentation.