Sometimes you get stuck with some problem that you just can’t figure out.
Your server is up and should work perfectly, but does it? Hell no, there is some odd error that you just can’t figure out. In my case, it was a problem with my mail server. I could send emails, but no way in hell was I able to get any emails.
At first, I thought the problem was my spam filter that stopped them, but looked through the logs and couldn’t find anything. But then I got to think of something. The domain my private server is on does not use a real host. It uses what is defined as a CNAME, which means it points to another domain name.
So what happened was that whenever someone tried to mail me, the mail got to my server but was rejected as being to the wrong domain since most e-mail clients translate the domain name into its real name.
So all I had to do to get it working, was to enable my mail server to accept mails for that domain and everything worked like a charm.