I am trying to configure postfix as per their instructions ( https://help.ubuntu.com/7.04/server/C/postfix.html ). Everything seems fine until the end when I test it. When I type "telnet mail.example.com 25," I get the following: Code: [email protected]:~# telnet mail.example.com 25 Trying 18.104.22.168... Connected to mail.example.com. Escape character is '^]'. If I enter "ehlo mail.example.com" after that, it doesn't do anything.