[Mailman-Users] Server doesn't gets any mails

[Sven Osterwalder]

Hello,
I've installed and configured Mailman as written in the README. 
Then I configured the domain, which the mails should go to (subdomain.domain.ch). 
When I send a mail to testlist at subdomain.domain.ch nothing happens. I even can't see if he gets any mail. How can I fix this ? So that the server gets the mails and mailman sends the message to the list ? 

Thanks & Greetings

Sven Osterwalder