Blocked Messages & Limits
15 articles
Resolving “Message blocked for your safety”
The “Message blocked for your safety” rejection occurs when Google’s threat-detection engine prevents an email from…
“5.1.1” Account does not exist
The “5.1.1 Account does not exist” bounce error (often reported as 550 5.1.1 User unknown or…
“Message not sent. Check network” (Mobile)
The "Message not sent. Check network" error occurs on the Gmail mobile app for Android and…
Troubleshooting “Empty Message” Errors in UI
The “Empty Message” error occurs in the Gmail web interface when the application attempts to process…
How to Bypass “Zipped File Blocked”
When Gmail blocks a compressed archive, the service displays an error banner stating “Blocked for security…
Why Gmail is Stripping Inline Images
When Gmail strips inline images, the recipient sees broken image icons, empty whitespace, or displaced attachments…
“5.7.1” Message likely unsolicited
The "5.7.1" Message likely unsolicited bounce occurs when Google’s inbound mail servers reject an email because…
“Too many recipients” (2,000 Limit)
The "Too many recipients" (2,000 Limit) error occurs when an outgoing message or daily sending stream…
Troubleshooting “Message too large” (Inbound/Outbound)
The “Message too large” error occurs when an email exceeds the maximum file size limit enforced…
How to Fix Google Drive Link Permissions in Gmail
Google Drive link permission errors in Gmail occur when the access configuration of a linked file…
“550 5.4.5” Daily Sending Limit Exceeded
The “550 5.4.5” Daily Sending Limit Exceeded error means your Google Workspace or Gmail account has…
Resolving “Attachment blocked for security reasons”
The “Attachment blocked for security reasons” error occurs when Google’s automated threat filters detect a forbidden…