Gmail 552 5.7.0
Blocked: content is a security risk
Gmail 552 5.7.0 means: blocked: content is a security risk. It is a permanent failure, so do not retry it unchanged. An attachment or content was judged a security risk. Share the file through a link instead of attaching it.
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
This message was blocked because its content presents a potential security issue. To review our message content and attachment content guidelines, go to File types blocked in Gmail.
Reply text
This message was blocked because its content presents a potential security issue. To review our message and attachment content guidelines, go to File types blocked in Gmail.
| Who sends it | Gmail and Google Workspace |
|---|---|
| Basic code | 552: Requested mail action aborted: exceeded storage allocation (RFC) |
| Enhanced code | 5.7.0: Other or undefined security status |
| Permanent or temporary | Permanent (5xx) |
| Verifying the list prevents it | No |
In practice
Gmail blocks messages with attachments it treats as a security risk, including executable files, some archives and documents with malicious macros. It also checks files inside archives, so renaming or zipping does not help. Share the file through a link from a storage service instead.
What the sender should do
An attachment or content was judged a security risk. Share the file through a link instead of attaching it.
Would verifying the list have prevented Gmail 552 5.7.0?
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 552 5.7.0 mean?
- Gmail 552 5.7.0 means: blocked: content is a security risk. It is a permanent failure, so do not retry it unchanged. An attachment or content was judged a security risk. Share the file through a link instead of attaching it.
- Should I retry after Gmail 552 5.7.0?
- No. It is a permanent (5xx) failure, so the same message to the same address will fail again. Fix the cause first. An attachment or content was judged a security risk. Share the file through a link instead of attaching it.
- Would verifying my list have prevented Gmail 552 5.7.0?
- 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.
The same code elsewhere
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