Communications Express allows users to select any year only till the year 2006. It does not allow selection of any other year after 2006 in all the views.
Communications Express does not recognize wild cards for searching Events or Tasks.
Users subscribed to a shared calendar with Availability and Invite permissions are unable to view the shared calendar.
Communications Express does not allow editing of Events and Tasks that are imported from one calendar to the other (with allow... permissions set on both), for the same calendar owner.
Communications Express has a hard dependency upon upgrading the UWC component of JES4 with Messaging Express and Calendar Express of JES3. A JavaScript error is displayed when users click on the Options Tab under Calendar.