This is the newest of the freeware programs I have tried and I have to say that I really like this program. It has caught every virus in emails as it was being downloaded to my computer, an alarm goes off and the I could quarantine it or delete it.. It will scan in coming and out going emails. The free version can be found here. Avast Personal is free for personal use.

At first I did not think I was going to like Avast. It made some changes to my email settings that I was not happy with, until I understood what the program was doing.
Avast sets itself up as a type of server on your machine. All incoming and outgoing mail has to go through Avast. This way  - No viruses in and No viruses out. If you happen to pick up a virus for file sharing or a downloaded program, it will not allow you to send any messages out with a virus which I have really come to like.

After downloading and installing Avast, you will get a screen asking what protection you would like. I always check "allow Avast to scan all existing email accounts" and "allow Avast the protect all email accounts added in the future". You also have the choice to "not" have it protect any email account - be sure not to put a check mark there.

After installation, you will notice 2 blue spheres in the system tray on the bottom right of the screen. The one with the letter "i" is the Virus Recovery Database Generator. You can right click it and go to "What is the VRDG?" to find out more about it. The other blue sphere has a letter "a" on it and this is the one you will use most.

To do a full system scan, right click the blue sphere with the letter "a" and then click "On Access Protection Control". Set the resident protection "High". Now close the window. Now right click the same sphere again, the click on "Start Avast Antivirus". This will start the actual system scanning program. In the opening window you will notice that it is scanning memory. There will also be a link there where you can register the program. Click on the link and register the program. in a few minutes you will get an email with your registration number. Copy and paste it into the registration box and then you can start using the program to scan your system.

You will have to manually scan your system with the personal program.

You may notice that the sphere with the "a" in it will spin quite a bit. I tends to do that when it is scanning and protecting you system. Don't let it worry you as it is doing it's job.