Naked Line Feed Characters

If you see this error reported by your mail server or mail client:

           451 Failed Naked LF see

This occurs because your client or the original client that sent this mail message sent LF characters without preceeding them with CR characters. This is faulty behaviour and not permitted by the SMTP RFC.

We offer the following solutions:

  • If possible correct the mail client.
  • The mail client may well be a malicious program sending spam or a virus in which case it can be safely ignored.
  • If you cannot fix the mail client and you don't mind breaking the rules as defined by the SMTP RFC then ask the manager of the system in question to set: g_lf_fix "TRUE" in surgemail.ini. That will tell SurgeMail to attempt to repair the message.