Did You Know? Creating a Reminder from an Email
Did you know that you can create a reminder from an email in Zimbra?
This is actually a bit of a workaround, but it is very helpful.
Right-click the email from which you want to create a reminder, and select Create Task.
In the Task tab, set the date and time for your reminder. In this example, at 4:00pm on September 22, a reminder window will pop up in my browser window.