Transferring contacts, or "Address Book", is commonly done in conjunction with transferring email. Some email programs have transfer tools, but with others, you have to export/import .... typically via a CSV file. Some people keep their address book in their webmail, so consider that when transferring from/to. There are even some people who depend wholly on Outlook's "Auto-Complete" list for their address book. To extract those contacts, you will need the NK2 tool from Nirsoft. NK2 refers to the filename that Outlook stores those names/addresses in.

Note that contact lists are notorious for needing "data cleaning" ... which can take a lot of time, even if you know some Excel tricks.