550 5.7.24: Suspicious entries in your SPF record
Gmail returns 5.7.24 (or 451 4.7.24) when the sending domain’s SPF record contains entries it considers suspicious. Google does not list which entries, so audit the record: remove over-broad IP ranges, +all, and includes for services you no longer use, and keep it to one record.
The exact messages
Gmail / Google Workspace
550 5.7.24 The SPF record of the sending domain has one or more suspicious entries.
Gmail / Google Workspace
451 4.7.24 The SPF record of the sending domain has one or more suspicious entries.
Why it happens
- The record ends in +all, which authorizes every server on the internet.
- Very wide IP ranges (for example a /8 or /16) that authorize far more than your real senders.
- Leftover includes for tools you stopped using, or entries copied from a template.
How to fix it
- Replace +all or ?all with ~all or -all.
- Narrow ip4:/ip6: ranges to the specific addresses your mail actually leaves from.
- Remove includes for services that no longer send for you, then re-check the record.
If you send cold email
Guides that tell you to "just add +all so nothing fails" cause exactly this. An SPF record should list only the services that really send your mail.
How WarmHawk handles it
WarmHawk checks SPF, DKIM and DMARC for each sending domain against live DNS and keeps "could not check" separate from "failed", so a flaky resolver never looks like a broken record. New mailboxes warm up by sending to partner inboxes and recording where each email landed, so an authentication problem shows up in the warmup results before the mailbox graduates to campaigns. How WarmHawk works →
Check your domain now
These free checkers read your live DNS: no account, up to 15 domains at once.
Related bounce codes
Sources, checked 2026-09-29: Google Workspace: Gmail SMTP errors and codes. Have a different bounce? Paste it into the decoder →
Questions
5.7.24 questions
What does 5.7.24 mean?+
Gmail returns 5.7.24 (or 451 4.7.24) when the sending domain’s SPF record contains entries it considers suspicious. Google does not list which entries, so audit the record: remove over-broad IP ranges, +all, and includes for services you no longer use, and keep it to one record.
Is 5.7.24 a temporary or permanent error?+
Both forms exist. A reply starting with 4 (such as 4.7.24) is temporary, and the sending server will retry; a reply starting with 5 is permanent, and the message will not be retried until you fix the cause.
How do I fix 5.7.24?+
Replace +all or ?all with ~all or -all. Narrow ip4:/ip6: ranges to the specific addresses your mail actually leaves from. Remove includes for services that no longer send for you, then re-check the record.