This article is detailed at apple.com and reproduced / edited here for clarity.
Please visit apple.com here for more information: http://support.apple.com/kb/HT2480
To add an Exchange account to your iPhone or iPod touch:
Tap Settings >> then Mail >> Contacts, Calendars >> Add Account >> Microsoft Exchange.
Note, you can configure only one Exchange account per device.
On the next screen enter the following:
- Your primary email address for email
- Leave Domain blank
- Your primary email address again for username
- Your password
Your iPhone (or iPod touch) will now try to locate your Exchange server using Microsoft's Autodiscovery service.
If the server cannot be located, the screen below is shown.
Enter ex.sbwh.net in the Server field.
Note: Do not enter anything for domain. The email and username will be the same.
Note: This is a sample screen DO NOT copy the below screenshot information.
Choose which type(s) of data you would like to synchronize: Mail, Contacts, and Calendars.
Note that by default, only 3 days' worth of email is synchronized.
To synchronize more, go into Settings, then Mail, Contacts, Calendars, select your Exchange account, and tap on Mail days to sync.
Note that after configuring an Exchange ActiveSync account, all existing contact and calendar information on the iPhone or iPod touch is overwritten. Additionally, iTunes no longer syncs contacts and calendars with your desktop computer.
