Email provider · 5.x.x permanent failure
Every SMTP 552 response on record from Google (gmail.com, googlemail.com), with the verbatim text, the enhanced status code, a severity rating and a plain-English fix.
The message was rejected for exceeding a size or storage limit, either the recipient's mailbox allowance or a maximum message size set by the receiver.
smtp;552 5.2.2 The email account that you tried to reach is over quota. Please direct the recipient to https://support.google.com/mail/?p=OverQuotaPerm - gsmtp
The recipient's mailbox is full or over its storage limit. There is nothing to fix on the sending side; delivery may succeed later once they clear space.
Provider documentation
SMTP; 552-5.2.3 Your message exceeded Google's message size limits. Please visit http://mail.google.com/support/bin/answer.py?answer=8770 to review our size guidelines.
You are sending to this receiver faster than it will accept from your IP or domain, and it has stopped taking the message. Cut the send rate, spread volume over a longer window, and requeue.
Provider documentation
SMTP; 552-5.7.0 Our system detected an illegal attachment on your message. Please visit http://mail.google.com/support/bin/answer.py?answer=6590 to review our attachment guidelines.
The receiver refused the message for good and points at a policy or security problem (enhanced status 5.7.0). Use the wording above to pin down the exact fix.
Provider documentation
Postmaster & documentation
The message was rejected for exceeding a size or storage limit, either the recipient's mailbox allowance or a maximum message size set by the receiver. At Google, it is a permanent rejection, and the specific reason is in the enhanced status code and message text of each response below.
Match your bounce text to one of the responses below and follow its guidance. Recipient-side wording means fix the address. Authentication or reputation wording (SPF, DKIM, DMARC, blocklist) means fix your sending setup, and check Google's postmaster documentation.
