I have been trying to resolve an issue where my mail client cannot connect to any server on tcp port 25. I have attempted to use a number of different relay servers as well as my employer's server. They are all being blocked.
Verizon is denying this is the case. I even had one of their support personel tell me the issue is because my IP address is black listed.
I know this is not the case though since I can telnet to my employers server on another port that is used by mail services.