Outlook - How to find auto-complete list of emails?

Question

When you type an email address in a new message in Outlook, it auto-completes from a list of emails you previously wrote too.
Where can I find this list of emails\users?

Answer 1

Outlook builds this list over time as you send and receive email. Names are stored in .nk2 files, which are binary files and cannot be edited simply using a text editor. There is, however, a tool which can edit these files called Nk2Edit, which is completely free for personal use at your home.

Depending on your Office version, these files are stored in different places, as described here.