I want to delete someone's email account without deleting their access to the domain/network. How can I do that please?Thanks....

Disable mailbox, removes the mailbox only and the windows account is left in AD.

How/where do I do that?

Use the Exchange Management Console, locate the user in the Receipients container and select them. On the Actdions pane, click the "Disable" button to disassociate the mailbox with the user account. If you remove the mailbox, it will also disable the user account. Very confusing, IMHO; the Exchange management console should not be able to create or delete users if Microsoft truly wants to separate user admin from mailbox admin. I liked it better when using Active Directory Users and Computers.

On the Exchange System Manager console I have a "Recipients" folder but under that all I see is "Recipient Policies", "All Address Lists", "All Global Address Lists", "Offline Address Lists", "Recipient Update Service", "Details Templates", and "Address Templates". In none of those can I find a way to do what you are suggesting. What am I missing?

Never mind...I did it from the Active Directory. Thanks for all your help everyone!