Gmail 421 4.7.32
Rate limited: From not aligned
Gmail 421 4.7.32 means: rate limited: From not aligned. It is a temporary failure, so your server retries it. The From domain does not match the domain that passed SPF or DKIM. Sign DKIM with the From domain, or use a return-path on the same organisational domain.
Gmail’s exact wording
Quoted from Google Workspace Admin Help: Gmail SMTP errors and codes, checked 2026-11-05. Placeholders are Gmail’s own.
Reply text
Your email has been rate limited because the From: header (RFC5322) in this message isn't aligned with either the authenticated SPF or DKIM organizational domain. Learn more about DMARC alignment. To learn more about Gmail requirements for bulk email senders, visit Email sender guidelines.
| Who sends it | Gmail and Google Workspace |
|---|---|
| Basic code | 421: <domain> Service not available, closing transmission channel (RFC) |
| Enhanced code | 4.7.32: Gmail-specific, not in the IANA registry. Its subject digit puts it under 5.7.0 other or undefined security status. |
| Permanent or temporary | Temporary (4xx) |
| Verifying the list prevents it | No |
In practice
DMARC alignment means the domain in the visible From header matches the domain that passed SPF or DKIM, at the organisational level. A newsletter sent as [email protected] but signed only by the platform's own domain fails alignment. Set up custom DKIM for your domain, or a custom return-path, on the sending platform. Alignment is checked on the organisational domain, so mail.yourdomain.com aligns with yourdomain.com under relaxed alignment.
What the sender should do
The From domain does not match the domain that passed SPF or DKIM. Sign DKIM with the From domain, or use a return-path on the same organisational domain.
Would verifying the list have prevented Gmail 421 4.7.32?
No
This reply is about your sending setup, the message or the receiving system, not about whether the address exists, so verifying the list will not prevent it.
Common questions
- What does Gmail 421 4.7.32 mean?
- Gmail 421 4.7.32 means: rate limited: From not aligned. It is a temporary failure, so your server retries it. The From domain does not match the domain that passed SPF or DKIM. Sign DKIM with the From domain, or use a return-path on the same organisational domain.
- Should I retry after Gmail 421 4.7.32?
- Your sending server retries it automatically, because it is a temporary (4xx) failure. Investigate only if it keeps coming back over several hours.
- Would verifying my list have prevented Gmail 421 4.7.32?
- No. This reply is about your sending setup, the message or the receiving system, not about whether the address exists, so verifying the list will not prevent it.
Sources
- Google Workspace Admin Help: Gmail SMTP errors and codes (checked 2026-11-05)
- RFC 5321: Simple Mail Transfer Protocol, section 4.2.3 (reply codes) (checked 2026-11-05)
Registry and provider wording is quoted exactly; guidance is written by the SimpleVerifier Team.
SimpleVerifier Team · Last checked against the sources 2026-11-05