To add an Exchange account to your ipad/iphone or ipod, go to Settings > Mail, Contacts, Calendars > Add Account > Microsoft Exchange.
If the settings can’t be automatically verified, you will be taken to the next screen for you to enter the server name manually
Choose which type or types of data you would like to synchronize:
Mail, Contacts, and Calendars. Note that by default, only three 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 device is overwritten.