Hi, I am running a Postfix/Dovecot email server (on Debian) and installed it following that ISPConfig tutorial. Everything works great since a few years and I never had any trouble withit, except: About a year ago I wanted to use my email address to create an account at http://www.uniteddomains.de - weirdly their system did not accept my email as a valid email address (with a cryptic error message) .. after trying around for quite some time, I tested to use my gmail address and surprise - that worked! So I figured "Oh well... maybe they only accept commonly known email domains like gmx, gmail etc".. and didn't care about it too much anymore. However, today I stumbled over another website https://www.cineplex.com/connect where I encountered the exact same problem.. this time with an error message saying: "Successfully established connection" .. like, yeah ... that sounds like an error to me! .. oO Anyway, I could not use my email address to create an account. However, gmail worked like a charm again. In both cases it looked as if the website would talk to my webserver and verify something.. and apparently, my Dovecot did not answer what they wanted to have as an answer. Does anyone have any idea what the issue could be? It's not super dramatic, but just .. I wonder what it is. And it would be convenient if I could just use my regular email address on these sites. Thanks, Kira
They probably tried to connect to postfix, not dovecot. Check your mail.log to see what they tried to check and with which error it failed.
I just checked /var/log/mail.log while trying to use my email address to register at their site. Nothing shows up in the log ... Anything else where I could check logfiles?
When nothing shows up in the log, then this service did not contact your server. Maybe you have an issue with your dns record, use e.g. intodns to check if everything is fine with the DNS setup of this domain.
I just checked, it says: I guess that's the issue I have no real experience with MX records .. and always thought they are somewhat optional (specially since I never had any problems with my email).. so, what do I need to do here? How does a proper MX record look like?
Add a MX record that points to the hostname of your mail server (or to a A-Record which points then to your mail server).
Totally forgot to answer .. the MX record did the trick and I can now use the email address with these websites Thank you~