Hello,
If you click on the mailing list from within webmail, you'll see the following settings:
As you can see, there's a field for the list's Reply-To address. You can set this to the list address, the poster address, or a custom address. It sounds like you might see good results setting it to the address of one of your moderators or admins. Let me know if this helps!
Jorel Haggard
System/Network Administrator
SmarterTools Inc.
www.smartertools.com