Mail server problems

When i validate my virtual servers i get this error:
Mail for domain : The mail server is not configured to receive email

I am not able to configure the email account on thunderbird either. I tried sending a mail via squirrel mail and it showed no problems. Only the incoming mail is troubling a lot.

Howdy,

Hmm, what is the output of these two commands:

netstat -an | grep :25 postconf -n