We have a very strict firewall at work. I can't open any ports, and I think all but HTTP is shut down.
I have accounts with three services I often use: Yahoo messenger, AIM and google (jabber).
When using my AIM with iChat, there's no problem at all. iChat logs on without problem, it doesn't even ask anything about proxies and such.
Yahoo messenger won't log on with default settings on, but there's a funky little feature under "network preferences" called "Firewall with no proxy". When this option is checked, Yahoo logs on without further problems.
I tried searching for Yahoo messenger HTTP proxy servers, and found this:
http://au.help.yahoo.com/help/au/mesg/unix/unix-06.html
But even with these settings enabled in Adium, I still couldn't connect, while the old messenger application logged on without problem...
I really want to start using adium on a regular basis - If you guys can fix this you will be my heroes.