I work in a somewhat unique environment which currently has no email to desktop capability. I am using SLES 11.2 and Zimbra 8.0.3 Open source edition a a pilot project. The managers have always maintained tight control of users communications. The system is setup and working great, however the upper management is reluctant to allow the system unless they can maintain control of user to user communication within the site.
What they have assigned as a stipulation to the usage of any email system within the company is to either restrict users from emailing each other, or to have their sent emails held until approved from their departmental manager. I would prefer the least restrictive option.
I'm thinking that users send an email upon which a rule then moves it into a holding folder. Then the manager can review and release back into the system.