What does 552 mean?

SMTP 552 indicates storage or size exceeded:

What it means:

Your message cannot be delivered due to size constraints. Either the message is too large or the mailbox is full.

Common causes:

Message size limit exceeded: Attachments or content too large. Mailbox quota exceeded: Recipient's storage full (permanent vs 452 temporary). Server policy: Maximum message size restricted.

Typical message examples:

"552 Message size exceeds limit" "552 Mailbox full" "552 Message too big"

Response:

For size limits: Reduce message size, compress attachments. For full mailbox: May suppress if persistent; user may be inactive.

552 says "too big to fit." Either the cargo is too large or the dock is full.