Gmail to enable virus scanning.

Googling Google blog has this post about the virus scanning feature to be added soon to Gmail. Googl mail has already a built in capability of blocking attachments with some suspect extensions; I had to rename various attachments with .zip or .exe extension to bypass the filter.
The Gmail help center was updated yesterday with these information:

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.

The last sentence sounds interesting: in this way you'll be aware of attaching a virus before actually send the email.
I'll look for details in the next days.