I've recently seen a few emails with uuencoded documents/files embedded directly in the body-text, i.e. not as an attachment.
These hit e.g. rules such as: 1.8 DISGUISE_PORN_MUNDANE BODY 1.7 OBSCURED_EMAIL BODY 1.1 HTTP_EXCESSIVE_ESCAPES 0.8 USERPASS 0.6 UPPERCASE_50_75 giving a total of 6 points. Has anyone already dealt with this? /Per Jessen, Zürich