@nick405060, why down-voting a comment?
Why are you trying to index Exchange Contacts? Assuming people adding and removing contacts all the time, how do you plan to track it? do you plan to constantly index it?
In any case, as far as i am aware, the contact list for each user is located in Personal Folder File, or in the Exchange account.
read here: https://www.transend.com/help-ll/Address%20Books/AddressBook-ExchangeOutlook.html
People like to post too-granular questions, but this isn't one of them. I cannot give a higher-level description of the problem beside what I stated. There are many business reasons for ingesting Exchange contacts.
Link is helpful, thanks