No, it's not likely to be anything else. You can test it yourself with the following:
Code:
ping alt2.gmail-smtp-in.l.google.com
ping 66.249.93.114
telnet alt2.gmail-smtp-in.l.google.com 25
telnet [66.249.93.114 25
That should tell you if you have a DNS problem or if you can connect to the server.