How does anti-virus scanning work?Each time you send and receive attachments, Gmail automatically scans them for viruses.
If a virus is found in an attachment you've received, our system will attempt to remove it, or clean the file, so you can still access the information it contains. If the virus can't be removed from the file, you won't be able to download it.
If a virus is found in an attachment you're trying to send, you won't be able to send the message until you remove the attachment.
Google already has excellent spam filtering and phishing detection, this is another way Google will gain "trust" points with their users. Right now GMail only blocks .exe files which have a high probability of being viruses. By disallowing .exe files, most viruses don't get through, however a full fledged anti-virus feature should help eliminate viruses completely.