If there is a public address book on the server and the server is configured correctly, you can use the contact application to search the public address book and add contacts from it to the device contact list.
Select the People application and tap the search icon (magnifying glass). Begin to enter text in the search bar. Contacts from the People application that meet the search criteria will display. Tap search Outlook directory to initiate a remote lookup of contacts on the public address book that meet the search criteria.
You can then add contacts, from the list that the remote lookup returns, 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. Tap search Outlook directory to initiate a remote lookup of contacts from these applications.