I split this thread so it's easy to find and can focus on this topic.
Since you need live backups and PDA/Mobile support, you'll want the Network Edition which includes these features and many more.
Zimbra's AJAX web client works on PC's, Mac's, and Linux OS. So the multi-OS support is not a problem but actually encouraged! Your Mac user's will enjoy our iSync adaptor(beta coming soon) which will give them two-way sync with their native Apple applications.
Zimbra supports an unlimited number of distributions lists that can be managed from the command line or from the admin UI.
For AD Zimbra can use AD as the master for auth and/or GAL. This is a simple configuration in the admin UI.
Anything I missed? |