Doesn't Microsoft licensing Exchange ActiveSync help its competitors?

Question

Why does Microsoft license Exchange ActiveSync? Not licensing it will only help them sell more proprietary stuff, right?

Or, is Exchange ActiveSync only a subset of what Microsoft Outlook supports through MAPI?

Answer 1

I discovered a Wikipedia article that lists the features that are licensed to corporations. So, feature sets are licensed and not the complete protocol.

Also, it seems not licensing raises some antitrust issues. This is what I've found out for now, but if anyone has anything to add or correct please feel free.