Microsoft Exchange protocol and Microsoft Exchange ActiveSync protocol are not the same and I will use the words Exchange and ActiveSync to respectively to refer to them in the susequent answer. Mac Mail supports an Exchange account but not ActiveSync account.
ActiveSync protocol was originally deviced to sync outlook data with Windows Mobile 5, 5.5 or 6. Exchange ActiveSync enables one to check an MS Exchange Email on a mobile device using an internet connection. Unlike the initial implementations the proximity of the mobile with a PC or Mac running outlook is not required. All synching happens via the internet.
You can configure ActiveSync exchange account on a mobile device such as iPhone, iPod, iPad, a Android device, Window Mobile-8 device or on a BlackBerry. Most corporates will enforce the ActiveSync account to be the administrator account to incorporate certain restrictions such as compulsory password/pin restrictions, screen-lock-timeout restrictions and also, the complete mobile device can be wiped of remotely. ActiveSync exchange account can also do the tracking, that means, if your lose you mobile device and an ActiveSync account has been configured in it, you will be able to track the device - the locatio etc., remotely.