I have a virtual server with 3 domains on it sharing the same VPS IP. I use Webmin/Virtualmin to manage it. I have 2 problems: mx.domain3.com does not work. I get "invalid host" when trying pop3 login. But I can pop3 login to domain3.com as user.domain3 There is also no DNS record for mx.domain3.com. Domain 1 + 2 have. How to set that mx.domain3.com ? Domain 1 and 2 work, but: I can not pop3 login with user@domain#.com but with user.domain# it works. Same for telnet login. I presume it's Postfix related, but so far no luck fixing it. What can I do next?