421 4.7.40: no DMARC record, rate limited
Gmail is rate limiting your mail because the sending domain has no DMARC record, or its record sets no policy, which Gmail requires of bulk senders.
- Gmail
- Provider
- Temporary (4xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 421 4.7.40
- Provider
- Gmail and Google Workspace
- Temporary or permanent
- TemporaryThe sending server keeps the message and tries again later.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
421 4.7.40 Your email has been rate limited because the sending domain doesn't have a DMARC record…
What it means
Google's sender guidelines require bulk senders to publish DMARC for their sending domain, though the policy may be p=none. Either the domain has no record at _dmarc, or the record it has carries no p= tag, so Gmail has rate limited the message. This is the code Google's SMTP reference lists; its sender guidelines FAQ gives 4.7.31 for the same wording. The permanent form is 550 5.7.40. Publishing a valid record fixes it, and p=none meets the requirement while you collect reports and fix any alignment gaps.
Common causes
- No DMARC record is published at _dmarc for the From domain.
- The record is malformed, or lacks the p= policy tag.
- The record sits on the wrong host name, such as the bare domain instead of _dmarc.
How to fix it
- 01Look up your domain's DMARC record to see what Gmail sees.
- 02Publish a TXT record at _dmarc.yourdomain with at least v=DMARC1; p=none, plus a rua address for reports.
- 03Check that SPF or DKIM aligns with the From domain before moving the policy beyond none.
- 04Let deferred mail retry once the record is live.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
- Gmail SMTP errors and codes (Google Workspace Admin Help)knowledge.workspace.google.com
- Email sender guidelines (Gmail Help)support.google.com
Related codes
- 4.7.31No DMARC record, in Google's FAQ.Google's sender guidelines FAQ lists 4.7.31 for mail rate limited because the sending domain has no DMARC record, or has one without a policy.
- 550 5.7.40No DMARC record, blocked.Gmail rejected the message because the sending domain has no DMARC record, or its record has no policy, which Gmail requires of bulk senders.
- 421Service not available.The receiving server is closing the connection and will not take mail right now. The reply is temporary, so the sending server keeps the message and tries again later.
Further reading
All 108 Gmail codesEvery code in the wikiPaste your own bounce