Amazing how they paint EAS as a better protocol than the "older" IMAP. EAS is a beast of a protocol. Just go to the protocol page at Microsoft[1] to get scared. The list of sub protocols and data formats is terrifying! This, compared to a protocol for which the basic session can be taught in five minutes tells a lot about the quality of both protocols.
Simplicity follows good engineering. EAS is way more complex than necessary.
It's horrible for many, many reasons. It is really quite an insane protocol. Mainly because it was ambiguous about so many key commands, what order they should be run in, the side effects, etc.. I picked up an app someone had written which originally only unsupported Outlook 2003(?), Outlook 2007 behaved differently to that, which behaved differently to Thunderbird, which behaved differently to Lotus Notes. Outlook 2007 even was even using a short to store ID, which I believe wasn't a unique ID and could change between sessions, so you had to search again for the message if you'd been disconnected. All because the protocol was just 'yeah, do something like this'.
There's a reason why IMAP was so ropey in many mail clients.
I have no idea about EAS, but let's not pretend IMAP is good.
Simplicity follows good engineering. EAS is way more complex than necessary.
[1] http://msdn.microsoft.com/en-us/library/cc425499%28v=EXCHG.%...