The windows XP firewall doesn't have outbound protection (essential in my opinion, see below) so shouldn't be blocking ashMaiSv.exe.
So it looks like AT&T are using SSL email on those ports I mentioned, which means currently avast can't scan your email.
There is little point adding those ports to the redirected ports as it would result in the email failing to be sent.
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Whilst the windows XP firewall is usually good at keeping your ports stealthed (hidden) it provides no outbound protection and you should consider a third party firewall.
Any malware that manages to get past your defences will have free reign to connect to the internet to either download more of the same, pass your personal data (sensitive or otherwise, user names, passwords, keylogger retrieved data, etc.) or open a backdoor to your computer, so outbound protection is essential.
- There are many freeware firewalls such as, Comodo (care required now it is a suite not to install the anti-virus element), PCTools Firewall Plus, etc. - Zone Alarm free works fine with avast and has a reasonably friendly user interface, however, the free version is becoming bloated with trial ware and is also crippled as far as outbound protection goes In the Program Control, configuration area, the slider will only goes as far as Medium protection, if you want more you have to buy the Pro version.
See A Forum discussion on free firewalls
http://forum.avast.com/index.php?topic=30808.0See
http://www.matousec.com/projects/firewall-challenge/results.php.
Many forum users are using all of the above:
PC Tools Firewall seems to have the least user headaches as it doesn't seem to be constantly asking the user questions about this and that.
I think you can see by my comments on Zone Alarm free you have to be careful that you are not using the pro trial version.
Online Armor for the most parts fine but it has caused some users grief after avast program updates and that is something you have to watch out for.
Comodo is now a suite and you have to do a custom install so as not to install the antivirus element, of all the firewalls listed this seems to be the noisiest in asking questions, depending on settings and elements used, so it could be daunting for those not to familiar with firewalls or their systems.