Able to send mail but recieve it

Heey there,

I’m currently trying out the Virtualmin GPL version for my own little server. Today I was trying to setup the email accounts, but there is a problem.

I’ve created a DynDNS host, with a email MX with it both directed to my server (called pikachu btw xD) in a NAT environment. But i’m able to send mail to (for example) my normal gmail account, but when I reply to it, it doesnt reach the email account i’ve made on my server.

I’ve checked the logs, cant find any good explantion for why it doesnt work because there is no error in the logs.

BTW I’m using Debian 5.0 and yes the ports are opened to my server.




What error are you getting when you reply – do you see anything?

Two potential issues come to mind –

  1. Did you setup port 25 on the NAT router to forward internally to your server?

  2. Many ISP’s block port 25. Are you certain that your ISP allows that?

If you can’t telnet into port 25 on your server from a system outside of your network, the issue is probably one of the above.


Yes i did forward port 25 to my server.

and if i remember correctly, if my ISP where to block port 25 setting up a relay in my config files would fix it right ?


if my ISP where to block port 25 setting up a relay in my config files would fix it right

It’s not quite that easy, unfortunately.

You can change the port Postfix listens on, that is correct.

And with that, you could get a desktop client to be able to talk to your server.

However, to get an email server (such as Gmail) to change what port it communicates with your server on – that requires you control that server.

That is, if you were to change Postfix to listen on port 5000, there’s no way to get Gmail (and all the other servers on the Net) to talk to you on port 5000 – they’ll keep trying to use port 25.

So the bad news is – if your ISP blocks port 25, it becomes quite difficult to host an email server there :slight_smile: