thunderbird/avg

hi guys.
i use thunderbird as my email client and have avg set up to scan all incoming emails.
if im lucky, avg will scan emails once every 20 times i open thunderbird and i even tested sending myself a .exe file and still it was not scanned. it seems to just scan randomly whenever it can be bothered.
does anybody know of a reliable email scanner that works well with thunderbird? not an ad blocker, not a program to scan my computer but one whose sole job is to scan emails and nothing else?
thanks

ps.

i choose 'a' over 'an' as i tend to pronounce the next word 'dot exe' but read it how you wish

First try sending and recieving this eicar test virus file to yourself a few times (both the com and zip separately and together) and see if it gets detected each time.

http://www.rexswain.com/eicar.html

I'm just wondering if it is actually scanning but not always telling you that it has. You may have to temporarily bypass AVG to be able to download it... it's totally safe.. it's only a text file with a universal test code recognized world wide as a fake virus.

You may be able to test whether the AVG is scanning the e-mail, or not. Send one to yourself and see if it says anywhere "Scanned by AVG".
I get e-mail from some of my friends that is marked so.