Saw a reference to some of this stuff the other day and wondered where it came from. Isn’t google (err I mean live search) great ;-)
Source: http://www.microsoft.com/about/legal/intellectualproperty/protocols/easp.mspx
Microsoft has licensing programs for many of the protocols that the company has developed to support communications among its software products. Communications protocols provide the rules for information exchange to accomplish specific, predefined tasks across a network connection.
Exchange ActiveSync Protocol: The Exchange ActiveSync Protocol enables mobile client devices, such as Windows Mobile-based Pocket PCs and SmartPhones, to synchronize e-mail, calendar, and contacts with a computer that is running Microsoft Exchange Server 2003.
Outlook-Exchange Transport Protocol: Microsoft also offers Independent Software Vendors a wide variety of ways to interoperate with Microsoft Exchange Server 2007 and Microsoft Office Outlook 2007, including a rich set of publicly documented APIs.
Outlook-Exchange Transport Protocol acts as a mediator between applications and back-end messaging system. From what I can find, it sound like it’s mapi.net? but don’t quote me on that!