Rated 5 out of 5 stars

Great replacement for "Exchange EWS Provider", if you don't need shared calendars (unsupported by Exchange ActiveSync)

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

I contacted the creator of "Exchange EWS provider":
https://github.com/ExchangeCalendar/exchangecalendar/issues/182

Maybe there is hope for EWS..