I have been using the free version of Avast for about 3 years now and it is excellent. It scans all emails both incoming and outgoing. When I receive an email that has a virus, it lets me know immediately, almost before it is loaded into my inbox, and gives me instructions on how to handle it. The only thing that might bother some, is that it scans each time you hook up to the internet, and this slows down the computer for 2-3 minutes. But I feel it is worth it. The updates are made daily at stratuo and never cause a problem.