On Thu, Feb 19, 2015 at 10:59:01PM -0500, Randy Jonasz wrote:
Hello,
I have an ubuntu 14.04 server running postfix. I wanted to test it with telnet on port 25. Alas I receive connection refused errors although I can ssh to the server fine and see that master is listening on port 25. I ssh'd to another machine outside of my lan and tried telnet from there. I was able to connect fine. Does anyone have any suggestions how I can troubleshoot this? My hosts.deny file is empty.
Here's the server's iptables -L output. My wan address is not listed. Thanks for your help!
Randy
[snip] It is possible that the ISP that you use from home is blocking outbound TCP/25 connection attempts? Try installing tcptraceroute on your home machine and see if you can contact any external mail servers, i.e. # host -t MX google.com. google.com mail is handled by 50 alt4.aspmx.l.google.com. ... # tcptraceroute alt4.aspmx.l.google.com. 25