Email provider · 5.x.x permanent failure
Every SMTP 552 response on record from Zoho (zoho.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 5.1.1 <[email protected]> Mailbox delivery failure policy error
The receiver refused the message for good and points at an addressing problem (the recipient or sender address itself) (enhanced status 5.1.1). Use the wording above to pin down the exact fix.
smtp;552 5.7.1 virus [name] detected by Zoho Mail
The receiver flagged the message as carrying a virus, malware, or a phishing payload. Rebuild it from a clean source and scan every attachment and link before you resend.
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 Zoho, 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 Zoho's postmaster documentation.
