Spam filter · 5.x.x permanent failure
Every SMTP 553 response on record from Email Security.cloud, with the verbatim text, the enhanced status code, a severity rating and a plain-English fix.
The mailbox name is not allowed, usually because the address is malformed, the domain is wrong, or the receiver will not accept mail addressed that way.
smtp;553 Message filtered. Refer to the Troubleshooting page at http://www.symanteccloud.com/troubleshooting for more information. (#5.7.1)
The receiver refused the message for good and points at a policy or security problem (enhanced status 5.7.1). Use the wording above to pin down the exact fix.
smtp;553 you are trying to use me [xx.messagelabs.com] as a relay, but I have not been configured to let you [x.xx.xx.xx, example.com] do this. Please visit www.symanteccloud.com/troubleshooting for more details about this error message and instructions to resolve this issue. (#5.7.1)
The receiver refused the message for good and points at a policy or security problem (enhanced status 5.7.1-2). Use the wording above to pin down the exact fix.
The mailbox name is not allowed, usually because the address is malformed, the domain is wrong, or the receiver will not accept mail addressed that way. At Email Security.cloud, 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 Email Security.cloud's postmaster documentation.
