rlm,
thanks for starting a new thread.
My guess is that it must be a collision with another program running on your computer. It doesn't even have to be a 'program', it can just be a hardware driver or something... It's quite difficult to say, but I can asure you that WinXP is now in fact our premium and most-supported platform and there are literally thousands of WinXP users who are using avast! without any problems.
![Wink ;)](https://forum.avast.com/Smileys/default/wink.gif)
Could you please try to describe what software and/or hardware you have installed? I'm particulary interested in the "low-level stuff", if you know what I mean. Also, If you had a program that could list all drivers loaded in the system, and you could deliver this list to me, that could be of great help, too. I understand that these 'experiments' are quite time-consuming, but there's a not-so-small chance that we'll be able to finally identify the conflicting piece of code, and you'd thus help the whole avast community.
![Smiley :)](https://forum.avast.com/Smileys/default/smiley.gif)
If you're not comfortable with sending this (kinda sensitive) information to this public forum, please feel free to send it to me as an IM or via e-mail.
Thanks a lot for you patience,
Vlk
BTW: Yes, it is possible to configure any e-mail client that's based on POP3 or IMAP4 to have it's traffic scanned by avast (provided you don't use SSL).