And once again the #Linux & #OpenSource friendly #Microsoft does its best to damage them, even by breaking its own standards.
Zarafa (now Kopano) has been helping businesses reducing their MS dependency (& costs) by providing an enterprise grade and viable #OpenSource alternative to Exchange and Office 365 for more than 10 years despite MS trying to break the Outlook connector with each update.
This is just the last one:
https://kopano.com/kb3172519-mission-reply-impossible/
Ditch Outlook!