[Mailman-Users] Mail problems

[shacky]

Hi.
I'm trying to install Mailman 2.1.9 on a system running Debian Stable (Etch
4.0) and Qmail+Vpopmail.
I installed Mailman with apt-get, I added a new virtual domain (
lists.mydomain.com) in Vpopmail and I configured the web interface.
I created a new test list, but if I try to subscribe myself by the web
interface I don't receive any confirmation message.
The /usr/sbin/sendmail executable is correct and points to the Qmail
installation.
In the Qmail logs I dont' see anything special, it seems Mailman isn't
sending any e-mail.

How I could solve?

Thank you very much!
Bye.