EWS - Exchange Online 2013 What is the required settings mailbox permissions in Microsoft Exchange EAC to activate and operate the EWS in Interaction Administrator? We have CIC 4.0 SU4 Thanks

The only permission required is impersonation. Here is an article that Microsoft provides on setting this up: https://msdn.microsoft.com/en-us/library/office/dn722376(v=exchg.150).aspx