That's how IMAP works. Everything is on the server.
The schedule should do what you want. The fact that the settings are not
sticking indicates a problem. If you User account an admin account?
1) Go to System Preferences --> Create a New User in Accounts. Switch to the
New User by logging out/in or use Fast User Switching.
2) Open Entourage and enter the account and make your selections in the
Schedule. Does it stick? If yes, then it's a problem in your regular User's
The terms User and Identity are often confused. See Tech Terms. Explains
some basics for Entourage that's also helpful.
Basic terms used with Entourage and the Apple Operating System (OS) to help
new users and switchers.
These links might be helpful:
IMAP Account < http://www.yqcomputer.com/
Mactopia Help: (one of those insanely long links)