http://thedailywtf.com/forums/51170/ShowPost.aspx

The WatchGuard Firebox which protects your network detected a message which may not be safe. 

Cause : The file type may not be safe. 
Content type : application/x-zip-compressed 
File name    : source.zip 
Virus status : No information. 
Action       : The Firebox deleted source.zip. 

Your network administrator can not restore this attachment.

Please zip the attachment and resend the message with the zipped attachment.

どうしろと(;´Д`)