McAfee WebShield SMTP 4.5 allows remote attackers to bypass email content filtering rules by including Extended ASCII characters in name of the attachment.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2000-1115
http://www.securityfocus.com/bid/1993
http://archives.neohapsis.com/archives/bugtraq/2000-11/0324.html