Email client applications use Internet Message Access Protocol to open email messages stored on a remote Web server. For example, you can set up email client apps like Apple Mail to view business ...

Details, solutions for Entourage It appears that in an effort to make the time it takes to check messages quicker, Microsoft Entourage chooses only to synchronize the Inbox with what is on the server.

I have only experience with UW-IMAP. It works very well for me, on a PPro 233 MHz. It uses ~/.mailboxlist with Mozilla mail, which is a convenient way to store subscribed folders in.