I have a signature on my outgoing email which contains a small gif file of my company's logo. I recently had a message returned saying "GFI Content Security detected a mail that triggered a content rule. The file was blocked by the attachment checking module at the file name checking stage. The rule is set to block all attachments which end with extension "gif"." I have been using this logo in with my messages for years and this is he first time I have had this happen. Is there any danger with gif files in email. Apparently a spam blocking company, GFi, http://www.gfi.com, makes software that blocks gif files.