Anti-virus scanning attachments
Gmail automatically scans every attachment for viruses when an attachment is delivered to you, and again each time you open the message. Gmail also checks for viruses in attachments you send. This helps to protect everyone who uses Gmail, and prevents the spread of viruses.
If our system is unable to scan certain files, you'll see an error that says "Oops... the virus scanner has a problem right now." You'll have the option to try again later or to download the attachment at your own risk. Please note that if Gmail can't scan the contents of the file, we can't guarantee that it's safe to view.
What happens if a virus is found?
If Gmail detects a virus on an attachment, we reject the message and notify the sender. If a message that’s already in your account has an infected attachment, you won’t be able to download it.
If an attachment you're trying to send is infected with a virus, Gmail will display an error message to tell you, but it won't clean the file. To send the message without that attachment, click the link in the error message that says Remove attachment and send.
If Gmail detects that you're trying to send an infected attachment, try running your anti-virus software in case your hard drive is infected. If you don't have anti-virus software, you might consider purchasing or installing one of the popular applications so you can protect your computer and information from viruses.