SMTP 552 5.7.0
Blocked for a security risk in the content (Gmail)
552 5.7.0 from Gmail means the message was blocked because its content, usually an attachment, presents a potential security issue. Executable files, some archives and documents with macros are common triggers. Send the file another way, such as a link to a shared drive, and resend.
Should you remove the address?
Keep the address; fix the sending side
Keep it. The block is about the content of this message.
Block. Retrying changes nothing until the cause on your side is fixed.
How it appears
This message was blocked because its content presents a potential security issue.
What causes it
- The message carries an executable or another blocked file type.
- An archive contains a blocked file.
- A document attachment was judged a security risk, for example because of macros.
How to fix it
In order — try the first one first.
- Remove the attachment and share it through a link instead.
- Don't rename file extensions to get around it; Gmail also scans inside archives.
Who sends it
Gmail and Google Workspace.
Gmail
Reply text This message was blocked because its content presents a potential security issue.
Gmail links to its list of blocked file types.
Common questions
- What does SMTP 552 5.7.0 mean?
- 552 5.7.0 from Gmail means the message was blocked because its content, usually an attachment, presents a potential security issue. Executable files, some archives and documents with macros are common triggers. Send the file another way, such as a link to a shared drive, and resend.
- Should I retry a 552 5.7.0 error?
- No. 552 is a permanent failure, so the message will never be delivered no matter how many times you try. Remove the address — repeated sends to permanent failures are one of the main signals mailbox providers use to throttle a sender.
- How do I fix SMTP 552 5.7.0?
- Remove the attachment and share it through a link instead.
- Is 552 5.7.0 a hard bounce or a soft bounce?
- 552 5.7.0 is a block rather than a classic hard or soft bounce. The rejection is about your sending (authentication, reputation, content or the recipient's policy), not about whether the address exists. Retrying changes nothing until the cause on your side is fixed.
- Should I remove the address after a 552 5.7.0 bounce?
- Keep it. The block is about the content of this message.
- Will verifying my list prevent 552 5.7.0?
- No. Content blocks are about the message itself.
Clean the list before the next send.
A bounce report only tells you about the addresses you already mailed. The rest of the list has the same kinds of dead mailboxes in it, and each one becomes a hard bounce recorded against your domain the moment you send.
- A real SMTP mailbox check on every row, before anything is sent
- Dead and mistyped addresses split out, so they never reach your sending tool
- Catch-all, disposable and role addresses flagged alongside
One plan, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.
Other 552 replies
Sources
- Source: Google Workspace Admin Help: Gmail SMTP errors and codes
- Source: RFC 3463: Enhanced Mail System Status Codes
Provider wording is quoted only where the provider publishes it.
Last reviewed 2026-10-22