550 5.7.24: suspicious SPF record, blocked
Gmail rejected the message because the SPF record of the sending domain contains entries that Gmail considers suspicious.
- Gmail
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 550 5.7.24
- Provider
- Gmail and Google Workspace
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
550 5.7.24 The SPF record of the sending domain has one or more suspicious entries.
What it means
This is the permanent form of 451 4.7.24. Gmail read the SPF record of the envelope sender's domain and found one or more entries it treats as suspicious, so it rejects the message instead of only rate limiting it. Google does not say which entries it means. Records that authorize almost anyone, through +all or huge IP ranges, are the obvious candidates, along with includes that pull in very wide ranges of their own. Tighten the record so it lists only the servers that really send for the domain.
Common causes
- An SPF record ending in +all or ?all.
- Very broad ranges in ip4 or ip6 mechanisms.
- Includes for unused services, or includes that authorize huge ranges themselves.
How to fix it
- 01Look up your SPF record and list every mechanism and include in it.
- 02Replace +all or ?all with ~all or -all.
- 03Narrow the IP ranges, and remove includes for services you no longer use.
- 04Check the corrected record with an SPF lookup, then send again.
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
Related codes
- 451 4.7.24Suspicious entries in your SPF record.Gmail found something in the sending domain's SPF record that it considers suspicious, and is rate limiting mail from your IP until it is fixed.
- 550Mailbox unavailable.The receiving server permanently refused the message for this recipient: the mailbox does not exist, cannot be reached, or the server rejected the message by policy.
- 5.7.24SPF check error.The receiving server could not complete the SPF check for the sender's domain, either because of a temporary DNS problem or because the SPF record is broken.
Further reading
All 108 Gmail codesEvery code in the wikiPaste your own bounce