Right lets start with a couple of questions
What version of ZCS are you running and on what O/S ? http://www.zimbra.com/forums/announc...r-profile.html
Not sure if you can turn it off but you could extend the time using :-
1) Is there a way to turn off the timeout function? If so how is it done?
These can also be performed within the Admin GUI, not just the command line.
su - zimbra
zmprov mc zimbraAuthTokenLifetime 1440m
These links may be of help :-
2) Is there a way to enable a desktop notification pop-up for new mail? Audio?
Zimbra Toaster for Windows and Mac