If there are public address book on the server and the server is set up correctly, the Contact application will enable you to search the public address book and add contacts from it to the device contact list.
Select the Contacts application and choose the search option.
A list of contacts that meet the search criteria will display on the screen. You can select the contacts you wish to add to your device contact list.
Using Remote Lookup While Composing Email or Creating a Meeting Request
You can use Remote Lookup in the Mail application while composing an email or in the Calendar application when creating a meeting request at the fields where you enter recipients.