[davidwtbuxton]

WebDAV wasn't a native Exchange protocol. But it was officially supported for Exchange server 2003/2007, and used heavily by Mac Entourage 2004/2008 to connect to Exchange servers as a supposedly "native" client.

In my experience, Mac Entourage clients connecting to suitable Exchange servers worked, but only for very few clients.

Vaguely remember that the Exchange servers would often get overloaded with the quantity of sync requests from the Mac clients.

This doc mentions that WebDAV was a previously-supported protocol for Mac Entourage: https://blogs.technet.microsoft.com/exchange/2009/01/20/ento...