Outbound email scanner problem...

[Wearyeyed]

Hey everybody!

I'm having a challenge with Avast on a Win 2003 machine running Smartermail mail on IIS.

I have tried searching for solutions, but only found several abandoned and unanswered posts...so I am a little frustrated, if not hopeful.

Anyway, the condition is this: emails with attachments fail to send when Avast email scanner is either off, or with the program uninstalled.

If the scanner is enabled, I have no issues.

Once Avast is *disabled* or uninstalled, the only way to send email with attachments is to disable the Windows native firewall.

My assumption, based on observing network traffic, is that between Smartermail and the outbound TCP port to a receiving mail server, Avast "does something" before sending-off the attachments.

This "something" is not occurring when the mail scanner is disabled, or the application uninstalled, and the hook that facilitates this "something" is not being released on disable or uninstall of Avast.

I have tried installing and uninstalling several times, including using safe-mode and the Avast utilities, but am unable to restore uninterrupted mail sending by any means with Avast not in the picture, except, as I previously noted, by disabling the firewall.

Additionally, Avast tech support offered nothing of value other than the usual uninstall strategies and a promise to look into the phenomenon...

Please note the firewall does *not* exhibit this behavior if Avast mail scanner is running; emails with attachments send fine in this configuration, firewall on or off.

TCP ports without Avast and when mail fails are typically in the 3k range and data never makes it to the receiving mail server, with Avast in place and scanning, successful TCP is over 10k range ports, just FYI.

Any insight would be greatly appreciated...

[Pondus]

Hmmm.....a strange one!
A shot in the dark....
Have You Tried setting the firewall back to Windows default and reboot?

[Wearyeyed]

Hmmm.....a strange one!
A shot in the dark....
Have You Tried setting the firewall back to Windows default and reboot?

Great suggestion!

Just tried it...unfortunately, same result.

I restored defaults on firewall, no Avast...no email sends with attachments.

Install Avast, no changes to firewall...joy!

Uninstalled Avast (safe-mode +Avast uninstall utility)...back to square one.

My next "try" will be to assign the mail server to a non-standard port, the idea being that Avast *might* intercept port 25 traffic for processing, but hopefully not notice SMTP/TCP traffic on other ports...but I do not have high hopes.

But, I am pretty convinced at this point it is not the firewall, per se, but some processing that goes on before data hits the outbound port.