The info will also be accessible through active directory
How to get User Data from the Active Directory[
^]
look for the "mail" attribute.
This should be the same data you get by accessing Exchange as John proposed. So take your pick :)
Neither answers your question - for an answer take a look at this:
http://stackoverflow.com/questions/2071668/how-to-get-contact-list-from-exchange-server[
^]
Heading and actual text of the question seems to be two different questions. The last alternative answers the "heading", while the former seems to answer the question "body" :-D
Regards
Espen Harlinn