Originally Posted by till
It is quite funny why you ignore my answers and ask the same question again and again and again while it is answered already.
You may use any IP or hostname that points to your server as pop3 and imap server. The domain sierra.qwerty.com does not work because you will have to create a dns record for it, explained above already.
For roundcube you can also use localhost as imap and smtp hostname but for any external imap client see my answer above and the other answers in this thread.
I don't mean to offend...
I tried ssl://localhost as well and got an error.
Is it the ports I'm getting wrong?