How to setup your iPhone with ActiveSync

Go to Control Panel to enable ActiveSync for your account.

To configure Exchange access on your iPhone

1. Open Settings -> Mail, Contacts, Calendars
2. Add Account -> Microsoft Exchange
3. Enter your e-mail address for e-mail (Ex. user@domain.com)
4. Enter your account ID as username (Ex. first.last_domain)
5. Enter your password
6. Click Next. If you get a certificate error click Accept
7. Enter "mob.exchangecarrier.net" as Server. Click Next -> Save.

Additional help is available via Apple's website here and here.