NK2 files are file extensions used by Microsoft Outlook to store data about users and their information, such as email addresses. These files enable the email app to automatically fill in the email address of your contact whenever you send a new message. However, while MS Outlook auto-generates NK2 files, it does not present a way of editing the entries. Here enters third-party apps such as NK2Edit. This practical and reliable e-mail client software allows users to create a new NK2 file or make changes to the existing ones. You can even use the app to back up your current NK2 files and restore corrupted ones which MS Outlook no longer reads. NK2Edit is a handy app to have when you need to edit NK2 files or modify the email and SMTP address of your MS Outlook contact. However, the program needs fresh, clean icons as it comes with an outdated, if not easy-to-use, interface.