Rated 5 out of 5 stars

Not as smooth as expected.

I was really excited after the testing phase and bought a license. Now that I work with it day by day I must say that it does not really satisfy my needs.

* Calendar is unstable:
Making appointments and processing answers to invites is really unstable.

Sometimes the appointment is not sent to others, once the event was duplicated locally and I was unable to process answers to the event. Event notifications show up delayed or not at all.

I already wrote the support, never got an answer.

When I need to create an event and invite others I need to use the OWA Web interface for now.

* Mailing part:
„Unread counter“ for mailbox folders are often outdated.

Apart from that the „mailing“ Part is really stable and ready for day-to-day use. Also the Addressbook integration works really good.

Edit: OK, wasn't aware of the fact the calendar is beta. The mailing part of the addon deserves 5 stars

This review is for a previous version of the add-on (0.7.7). 

The calendar is still in beta and not a promised or advertized feature.