Learn how to interpret common Simple Mail Transfer Protocol (SMTP) response status codes that affect Symantec Email Security.cloud clients, including:
These codes and messages can occur under the following circumstances:
Email Security.cloud
Email bounce backs occur when an email is sent to an Email Security.cloud client, and a rule is triggered by the email recipient's configuration.
Review the appropriate article for the message you're receiving for more information:
421 too busy
421 Service Temporarily Unavailable
450 Connection rejected by policy [7.7]
450 Requested action aborted [3]
450 Requested action aborted [4]
450 Requested action aborted [6]
450 Requested action aborted [9]
451 TLS/SSLv3 Connection required [11]. (#4.7.1)
452 Too many recipients received this hour
453 you are trying to use me [server-x.tower-xx.messagelabs.com] as a relay, but I have not been configured to let you do this. Please visit https://knowledge.broadcom.com/external/article?articleId=169652 for more details about this error message and instructions to resolve this issue. (#4.7.1)
460 too many messages (#4.3.0)
501 Connection rejected by policy [1]
501 Connection rejected by policy [7.x]
550 Invalid recipient
550 Requested action aborted [4]
550 sender envelope domain not allowed for sender IP address (#5.1.8)
This error occurs when a sender attempts to send an email and any one of the following are true:
553 DMARC domain authentication fail
553 mail rejected because your IP is in the PBL
553 Recipient mailbox is not allowed
553 Stray linefeeds in message (#5.6.2)
553 Sorry, your domain has been blocked
553 Sorry, your email address has been blocked
553 sorry, your envelope sender is in my badmailfrom list
553 Sorry, your IP address has been blocked
553 SPF (Sender Policy Framework) domain authentication fail
I have not yet been able to deliver your message
Recipient mailbox is not allowed (broadcom.com)
Sorry, your email address (addr) has been blocked