I can't seem to get the Email Reminder Zimlet working.
I had it working fine with Zimbra Open Source 5.something.

Since we have decided to use Zimbra as our district wide e-mail server we purchased Zimbra Network Edition and we are running = Release 6.0.2_GA_1912.UBUNTU8_64 UBUNTU8_64 NETWORK edition

The zimlet shows that is enabled and running but do not see a send & remind button when composing or replying to a new message and noticed it didn't create an Email Reminders calendar either for the users.