Gmail 550 5.7.24
Suspicious SPF record
Gmail 550 5.7.24 means: suspicious SPF record. It is a permanent failure, so do not retry it unchanged. Gmail rejected the message because of suspicious entries in your SPF record. Tighten the record and remove broad mechanisms.
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
The SPF record of the sending domain has one or more suspicious entries. For more information, go to Email sender guidelines.
| Who sends it | Gmail and Google Workspace |
|---|---|
| Basic code | 550: Requested action not taken: mailbox unavailable (e.g., mailbox not found, no access, or command rejected for policy reasons) (RFC) |
| Enhanced code | 5.7.24: SPF validation error |
| Permanent or temporary | Permanent (5xx) |
| Verifying the list prevents it | No |
In practice
Gmail found entries in your SPF record that it considers suspicious, such as +all, very large IP ranges, or includes that authorise far more senders than you use. Such records weaken SPF for everyone. Narrow the record to the services that actually send as your domain. The temporary form is 451 4.7.24, which rate-limits rather than blocks.
What the sender should do
Gmail rejected the message because of suspicious entries in your SPF record. Tighten the record and remove broad mechanisms.
Would verifying the list have prevented Gmail 550 5.7.24?
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 550 5.7.24 mean?
- Gmail 550 5.7.24 means: suspicious SPF record. It is a permanent failure, so do not retry it unchanged. Gmail rejected the message because of suspicious entries in your SPF record. Tighten the record and remove broad mechanisms.
- Should I retry after Gmail 550 5.7.24?
- No. It is a permanent (5xx) failure, so the same message to the same address will fail again. Fix the cause first. Gmail rejected the message because of suspicious entries in your SPF record. Tighten the record and remove broad mechanisms.
- Would verifying my list have prevented Gmail 550 5.7.24?
- 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)
- IANA: SMTP Enhanced Status Codes registry (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