Many of our users are receiving emails stating "auth credentials have expired". I assume their connection to Zimbra is timing out after x hours. Also, with others, they don't receive this message, but they stop receiving email. With a restart of Outlook this is solved.
I see the session timeout in the admin console, but I assume that is for the web interface.
Outlook 2010, 32bit.
Zimbra Enterprise 7.1.4