There has been a lot of speculation about the iPhone and its abilities to connect to Microsoft Exchange Server. For instance, Wall Street Journal columnist Walt Mossberg mentions in his June 26 All Things Digital column that, "It [the iPhone] can also handle corporate email using Microsoft's Exchange system, if your IT department cooperates by enabling a setting on the server."

Technically this is correct, as today iPhone users can connect to Microsoft Exchange using IMAP.  There are, however, some significant differences in the mobile device experience and IT professional capabilities supported by IMAP on the iPhone and those enabled by Exchange ActiveSync (EAS) for compatible devices.  EAS is a protocol that provides rich messaging experiences for over 200 different smartphones right out of the box.  These smartphones include Windows Mobile devices as well as phones from a broad range of 3^rd parties including Helio, Motorola, Nokia, Palm, Sony Ericsson and others.