Integrating Linux box into an NT network

I apologize if this is too “newbie” a question for this forum. I have a lot more experience with Microsoft OS’s than Linux at this point. I’d like to set up a RedHat 7.0 workstation that can log into our NT domain and set it up to retrieve mail from our Exchange server.

1) How do I connect to an NT domain?

2) What Linux mail clients work with an Exchange server?

All input is appreciated.