We are running SmarterMail version 15.0.5973 with Active Sync enabled for one of our users who has Outlook 2013 on his desktop and also has an iPhone and iPad (both running IOS 9.3.2 - the latest version).  If a meeting request arrives it can be accepted in Outlook 2013 and added to his calendar.  However, the same request still shows up in the Calendar Inbox on the iPhone and iPad even after being accepted in Outlook but does not appear in the calendar of either device.  

 

If a similar meeting request arrives and is not accepted in Outlook it appears in the calendar inbox of the iPhone and iPad and if you choose the Accept button it does nothing and stays in the inbox.  The mail syncing works fine and I have verified that calendar syncing is turned on with the iPhone and iPad devices.

 

We have another user with a similar setup but is using an Android smartphone but has none of these calendar issues.  Any ideas on how to get the calendar syncing to work on an iPhone and/or iPad?  Thanks.