Since Mac OS X Mail does obviously know about all these recipients, should it not be easy to import them into the Address Book? It is. You can easily harvest Mac OS X Mail's vast memory of all the people you mailed to build your contact list.
Add Addresses from the Mac OS X Mail Auto-Complete List to the Address Book
To copy people from Mac OS X Mail's auto-complete list to its address book:
- Select Window | Previous Recipients from the menu in Mac OS X Mail.
- Highlight all desired addresses.
- You can highlight multiple addresses by holding down the Option key while clicking.
- Press Shift to select an address range.
- Click Add to Address Book

