how does it tell if you are corporate users? what if you just select corporate users during first run?
A "corporate user" account is an IM account on a corporate server that has Live Communication Server 2005 or Office Communication Server 2007. Messenger: Mac 7 dropped support for LCS 2005 (which my company uses), so I'll be sticking with 6.0.3 for a long time.
Because it requires server software installed on a "local" system you can't fake a corporate account. They also use different protocols than the Internet/free IM servers.