There is no way to specify which accounts should use a proxy or not.
Submitted by Mikhail Gavrilov
Description of problem: There is no way to specify which accounts should use a proxy or not.
The problem is that to connect to internal corporate jabber server may only directly (bypassing the proxy). But ICQ has to connect through a proxy. It is necessary to configure each account to add a checkbox "use system proxy" and also add the ability to specify a username and password for the proxy. Because in the system settings you can not specify a login and password to connect to the proxy.
So I think NTLM also unsupported :(