Google has added a virus scanning feature to Gmail, complementing the existing virus protection based on blocking certain types of file attachments, such as executables.

Gmail will automatically scan all attachments users send and receive, the company revealed online.

The Web mail system will attempt to clean or remove viruses from infected attachments so that users can access the attachment's information; otherwise, users will not be able to download the attachment. Gmail will also prevent users from sending messages with infected attachments.

Until now, Google has protected Gmail users by blocking messages that carry attachments commonly associated with virus attacks.

Gradual roll-out

Google began rolling out the virus scanning feature this week, so not all users have it yet, a Google spokeswoman said Thursday. However, by the end of this week, all users will have it, she said.

Lacking this functionality put Gmail at a competitive disadvantage in the market, an analyst said: "This was one of the main features they didn't have that other providers did," said Marcel Nienhuis, an analyst with The Radicati Group.

A year ago, Google official told IDG News Service that the company was working on giving Gmail virus scanning capabilities. Google is licensing the new virus-scanning technology from an undisclosed third party.