Exchange Server 5.5 lets me easily control who can use POP3. Does Exchange 2000 Server have that control?
To control whether an individual can use POP3 in Exchange 2000, you must use the Microsoft Management Console (MMC) Active Directory Users and Computers snap-in on a machine running Exchange System Manager (ESM). Open the Active Directory Users and Computers snap-in, locate the user whose protocol permissions you want to change, and select the Exchange Advanced tab. The Protocol Settings controls on the Exchange Advanced tab let you control permissions for each user; using these controls, you can enable or disable HTTP, IMAP, and POP access.