I've successfully set up a VPS running Ubuntu 12.04 LTS and I have installed ZPanel CP on top of that.
I have got the IMAP server to work and it accepts the login (my email @ domain.com) and it accepts incoming emails. What I try to do is to connect to the SMTP server at port 25 but it just keeps loading and eventually it give's me the error that it can't connect. (Doing this through a client, Sparrow on a mac and the inbuilt one in iOS)
I have made sure that the port is open, I can send emails through it (With the inbuilt webmail) and I can send emails to myself (without authenticating) through a service I found online. (It denies sending email's to somewhere beyond my domain though.)
I wonder if any of you have any hint on what might be going wrong?