Apple products aren't historically used among members of corporate America. In the past, Microsoft has catered to business needs with products like BlackBerry. The emergence of the iPhone has changed Apple's strategy, especially since Apple supports syncing with Microsoft Exchange for iPhone 2.0 and higher.
To synchronize with the server, the iPhone utilizes the Exchange ActiveSync protocol, which is automatically enabled on Exchange servers. In addition to push email, users can securely sync contacts and schedules.
On the Server Side
Step-by-step instructions on preparing your Exchange server are available on the Apple Web site. Technical and prerequisite materials can be found on Microsoft's Tech Net forums. Today, Apple's iPhone 3.0 can only sync with one Exchange server, but you can set up more than one account through POP or IMAP. These accounts don't support push notifications, so the mail application will have to be open to check for new messages.
On the User Side
Setting up your iPhone is fairly straightforward. Simply go to the "Settings" menu and tap the "Mail, Contacts, Calendars" option. Under the "Accounts" heading, tap "Add Account" and select Microsoft Exchange from the next screen. Fill in the fields with the correct information, then hit the "Next" button in the upper right corner. From there, your iPhone will attempt to automatically fill in your serve information. If it fails, you will be prompted to enter the server information manually.
Issues with ActiveSync
As mentioned above, iPhone software doesn't allow more than one dedicated Exchange connection. iPhone 3.0 software allows for multiple calendars to sync with your device through the CalDav protocol, but does not allow integration between the calendars, which can be confusing. The recent announcement of iPhone 4.0, due to be released in the summer of 2010, will allow multiple Exchange connections. iPhone 4.0 software will be available for iPhone 3GS, but not for iPhone 3G or earlier.
Currently, the iPhone does allow you to sync contacts and events from the Exchange server without overwriting existing information on your device. This may result in duplicate entries but may be worth it if you have a lot of contacts on your phone. Google now offers synchronization through Microsoft Exchange so accessing calendars, email and contacts through Google products is now easier.