552 5.7.0 Gmail bounce: content blocked as a risk
What 552 5.7.0 means
Gmail blocked the message because its content, links or attachments look like a security risk.
Message text
This message was blocked because its content presents a potential security issue…
This is an excerpt: the provider's documentation shortens the message. Full text: provider documentation
Common causes of 552 5.7.0
- Content, links or attachments flagged as a potential security issue
How to fix 552 5.7.0
- Review the message content, links and attachments and remove anything suspicious.
- Check the message headers with email header analyzer before sending again.
Check your domain
Read the headers of a bounced messageRuns in your browser; nothing is uploaded.
Get your domain's deliverability score
Have the full bounce message? Paste it into the bounce code lookup and it will match the code and the provider for you. Open the bounce code lookup.
How to read 552 5.7.0
The first part, 552, is the SMTP reply code. Requested mail action aborted, exceeded storage allocation: the mailbox or message is too large. Replies that start with 4 are temporary and replies that start with 5 are permanent (RFC 5321 §4.2.1).
The second part, 5.7.0, is an enhanced status code (RFC 3463 §2) written class.subject.detail. Class 5 is a Permanent failure (5xx): the command was rejected and the sender should not repeat it unchanged (RFC 5321 §4.2.1; RFC 3463 §2).. Subject 7 is security or policy: authentication, authorization or policy refused the message. The detail number refines the subject, and providers may define details of their own, which is why one code can read differently at Gmail, Microsoft and Yahoo.
Do not keep resending the same message: a permanent failure repeats until the cause is fixed. Correct the cause, then send a new message.
Official source: knowledge.workspace.google.com. Last verified 2026-10-20.
Related guides
- How to create an SPF record (syntax and examples)
- How DKIM works and how to publish a DKIM record
- How to set up a DMARC record, from p=none to p=reject
Related codes
- 5.7.0 SMTP: security status
- 5.7.1 SMTP: delivery not authorized
- 5.7.23 SMTP: SPF validation failed
- 5.7.25 SMTP: reverse DNS failed
- 5.7.26 SMTP: authentication failed
- 5.7.27 SMTP: sender has null MX
FAQ
What does 552 5.7.0 mean?
Gmail blocked the message because its content, links or attachments look like a security risk. This is a permanent failure.
How do I fix 552 5.7.0?
Review the message content, links and attachments and remove anything suspicious. Check the message headers with email header analyzer before sending again.
Is 552 5.7.0 permanent, and should I retry?
552 5.7.0 is a permanent failure, so retrying the same message will fail again. Fix the cause first, then send a new message.