Ubuntu 12.04 with ISP CONfig Mail services were functioning fine until I had to do a DSL modem/router swap I can send mail but cant receive... I have looked at all of the port forwarding from the old modem and tried to move it over to the new and it all looks the same.. What ports need to be open to receive? Thanx Dave
Telnet to your external IP on port 25 if you receive a hello message the port is opened, and your problem is from something else. http://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol#Ports
Receiving Mail is normally Port 110 for POP3 and port 143 for IMAP. SMTP standard port is Port 25 (or Port 465 for SMTPS) which seems to be working for you. On the end of the day, it's all about the settings of your Mail Server.
Turns out despite opening ports 25 and 110 with application rules.. this zyxel needed portforwarding then the server needed to be added to a DMZ.. ultimately this modem/router doesn't port forward the way I need to.. I will be replacing it with a cisco 26xx with an ADSL WIC.. Any recomendations on which model and IOS?
In DMZ your machine is totally unsecured. Port forwarding should work with no problems to an DMZ Machine. Regarding the Cisco ADSL Modem/router, I would go at least for an 600 or 800 series device. Do not get an Linksys, even they're owned by Ciso for a few years already, it's not the same, much lower quality and spec. Would be all about how much you would spend and what's available in your country.
