I am having this same problem. i just did a swap for a client of mine
and on his new computer he has a new .nk2 file on his old computer he
has the autocomplete on and autoname suggestion when typing in a
letter in the "To." i looked in the %AppData%\Microsoft\Outlook\
location, but he does not have "Outlook.NK2" he has "MS Exchange
Settings.NK2"....i transfered it and it doesn't transfer his cache
autocomplete from his old computer. i did a search of all files and
folders with hidden files to be searched as well. Again, the MS
Exchange Settings.NK2 was the only thing that came up. i also tried
turning the autocomplete off and then back on to send a email to
myself and another person to see if outlook would make a new .NK2 file.
I figured out how to fix this problem. if you have a nk2 file like the
one i had "ms exchange settings.nk2" and put it on another computer in
the %AppData%\Microsoft\Outlook folder, and then after you launch
outlook and cant get your auto suggest names that are supposed to be
there like before, well if you look in the folder %AppData%\Microsoft
\Outlook folder after you launch the outlook, outlook will make a nk2
file called "outlook.nk2" while yours is in there. all that is needed
to be done is to, delete the one that says "outlook.nk2" and rename
your "ms exchange settings.nk2" file to "outlook.nk2" and everything
should be working properly like before.