When you start Microsoft Outlook 2013 or Outlook 2016 for the first time, your nickname cache (stored in the profilename.nk2 file) is imported into a hidden message in your default message store.
Note profilename is the name of your Outlook profile.
For example, if you are using a Microsoft Exchange account, the nickname cache is imported into a hidden message in the Exchange mailbox.
Note Outlook 2007 and earlier versions store the nickname cache .nk2 file in the following folder.
Windows XP Drive:\Documents and Settings\Username\Application Data\Microsoft\Outlook
Windows Vista and later versions Drive:\Users\Username\AppData\Roaming\Microsoft\Outlook
After the nickname cache is imported, the profilename.nk2 file is renamed to profilename.nk2.old. On the next start of Outlook, your nickname cache is not imported. Outlook 2013 and Outlook 2016 do not use the .nk2 file for maintaining your nickname cache. All updates to your nickname cache in Outlook 2013 and Outlook 2016 are made to the hidden message in your default message store.
Note If you have multiple Outlook profiles, the nickname cache from each profile is merged into your new Outlook 2013 or Outlook 2016 nickname cache on the first start of Outlook by using that profile. Therefore, you may find more than one .nk2 file renamed to .nk2.old.
However, there may be situations where you have to import a nickname cache file after this first-run nickname cache import process has finished. For example, a colleague wants to share their nickname cache with you and you want to update your existing nickname cache with your colleague’s data.
This article discusses how to import .nk2 files into Outlook 2013.
To import .nk2 files into Outlook 2013 or Outlook 2016, follow these steps:
Make sure that the .nk2 file is in the following folder:
Note The .nk2 file must have the same name as your current Outlook 2013 or Outlook 2016 profile. By default, the profile name is "Outlook." To check the profile name, follow these steps:
Click Start, and then click Control Panel.
In the Mail Setup dialog box, click Show Profiles.
Click Start, and then click Run.
In the Open box, type outlook.exe /importnk2, and then click OK. This should import the .nk2 file into the Outlook profile.
Note After you import the .nk2 file, the contents of the file are merged into the existing nickname cache that is currently stored in your mailbox.
Note The .nk2 file is renamed with a .old file name extension on the first start of Outlook 2013 or Outlook 2016. Therefore, if you try to re-import the .nk2 file, remove the .old file name extension.
For more information, visit the following Microsoft web sites: