Fix the MTA-STS TXT record

Why it matters

Senders ignore a malformed or duplicated MTA-STS TXT record and behave as though you have no policy. The record needs one v=STSv1 and an id of letters and digits.

The fix

1. Keep exactly one TXT record at _mta-sts whose text starts with v=STSv1; delete any other.
2. It must contain id= followed by 1 to 32 letters or digits (no dashes, dots or spaces). A timestamp such as 2026100501 works well.
3. Change the id whenever you change the policy file, so senders re-fetch it.

_mta-sts.example.com.  IN TXT  "v=STSv1; id=2026100501"

The examples use example.com. Replace it with your own domain.

Read the documentation ↗(opens in a new tab)

Related

• Reported by the MTA-STS and TLS-RPT check
• Publish an MTA-STS policy, starting in testing mode
• Nothing to do for MTA-STS on a domain that accepts no mail
• Make the MTA-STS policy file reachable
• Fix the certificate on the MTA-STS policy host
• Fix the MTA-STS policy file
• Switch MTA-STS from testing to enforce
• Turn MTA-STS back on
• Make the MTA-STS policy cover every MX host
• Raise the MTA-STS max_age
• Publish a TLS-RPT record
• Fix the TLS-RPT record