Issue :

In Microsoft Outlook 2013, when you attempt to manually import a nickname cache (.nk2) file using the /importnk2 command line switch, the nickname cache data may fail to be imported, and the .nk2 file is not renamed to .nk2.old as expected. No error message is displayed when this failure occurs, however, the names contained in the .nk2 file fail to be displayed as suggestions when typing in the To: CC: or BCC: fields in a new message.

Cause:

The .nk2 import process does not succeed when both of the following conditions occur:

the Outlook profile name contains a period (.) as in the below example:

John.Smith

the respective .nk2 files for the profile name above are renamed as:

John.Smith.nk2

Outlook 2013 is unable to recognize the matching .nk2 file name of profile names containing a period, when the .nk2 file also contains a period other than the .nk2 extension.

Resolution:

To work around this issue, rename the .nk2 file and replace the periods from the profile name with spaces. Using the examples above:

Profile name: John.Smith
.nk2 Filename: John Smith.nk2

Using this naming convention will allow the outlook.exe /importnk2 command line to successfully import the nickname data and rename the file to .nk2.old.

More Information:

980542 How to import .nk2 files into Outlook 2010
http://support.microsoft.com/kb/980542

Thanks & Regards

Rahul Thomas