Can't access SMTP outside of the server. What to check ?


i’m using the SMTP of my virtualmin server for the first time because i usually use Google Apps for my emails.

When on the server i can telnet to port 25 and get postfix answer
But outside of the server, i have an Operation Timed Out.

I have check the firewall on the Webmin and port 25 is opened.

What could i check elsewhere that could deny any connection ?


Where is your server located? Is it on a self-hosted machine or in a hoster’s datacenter?

If telnet to localhost and the server’s IP works when you’re logged on to the machine, but connection to the IP from the outside does not, it’s most likely an external firewall or router is blocking/not forwarding the port properly. You might want to verify that and ask your hoster/ISP about it if applicable.