17 Dec
2003
17 Dec
'03
11:17 p.m.
From: ichudov@algebra.com (Igor Chudov @ home) Date: Tue, 27 Aug 1996 11:20:56 -0500 (CDT)
Look at your sendmail.cf file for a humongous amount of email parsing rules.
Much better, look at rfc822. (I wouldn't consider *anything* that has the word "sendmail" in it a good reference). Hostnames will match the regexp [-A-Za-z0-9.]; those are the only legal characters in the hostname portion. Usernames ("domain-dependent local string") are much harder to what is and isn't legal. Read rfc822.