Exchange 5.5 & Lotus cc:mail

I have Exchange Server 5.5 running with Outlook on all of the client computers. I also have Lotus cc:mail running on a computer connected to a phone line to pull in mail for our cc:mail account. Going by the reading I have done I should be able tosend and receive my cc:mail through Outlook. What do I have to do to setup Exchange to send and receive cc:mail to the outside world. When I go into Exchange and look at the properties of each user I do see CCMAIL and an address.

Let me know if I need to provide more information.

Thanks for your help,
Dean