as already said. check dns resolution first, forget whether or not there's a response, does a ping pop.gmail.com return a first line like:PING gmail-pop.l.google.com (173.194.78.109) 56(84) bytes of data.64 bytes from wg-in-f109.1e100.net (173.194.78.109): icmp_req=1 ttl=48 time=12.7 ms64 bytes from wg-in-f109.1e100.net (173.194.78.109): icmp_req=2 ttl=48 time=12.6 mssee the ip? if it's not returning an ip, then there's a dns problem somewhere.try pinging the ip rather than the name, if that works, then again, it's a dns issue, you can set your pop/imap server using the ip instead of the name, it'll get you up and running, but it's not the recommended way, and doesn't provide for server failure.if you can ping the ip, but can't telnet to the ports, then there's definitely a firewall/iptable rule somewhere blocking it. if pinging the ip address fails, you'll need to run a traceroute to that ip, and see where it fails, and start troubleshooting from there. also, it may seem silly, but are you absolutely sure you can't connect?, when trying telnet, does it show a connecting to... message, followed by 'could not open a connection to the host', or do you just get a black window with a flashing white box in the top left corner?if it's the latter, it is connected.
