To set up Microsoft Exchange mail, make sure that your corporate environment is running at least Microsoft Exchange 2003 SP2 or Exchange 2007. If you can use Active Sync you mail system is likely to be set up for iPhone e-mail.
Under Settings, Mail, Contacts, Calendars, Add Account choose Microsoft Exchange.
Enter your e-mail address: firstname.lastname@example.org
Domain: your Active Directory domain
Username: typically your network username
Password: your network password
The set up will go away to try verify your account.
In the next screen:
Server: enter your company’s server name then click on Next
Leave each of Mail, Contacts and Calendars on if you wish to synchronize these. Choose Done.
The final screen shows the default settings which you can change if you wish. These include manually pushing mail to you. Leave this turned off if you are concerned about battery usage.
Your iPhone will then begin downloading all your mail, contacts and calendar items!
If you need to search your Exchange Outlook contacts click here!