Which file should be used to restore archived email messages for someone using Microsoft Outlook?

• A. Outlook bak
• B. Outlook ost
• C. Outlook NK2
• D. Outlook pst

Answer: (D)

Outlook stores local mail data in PST files, which are used for personal storage and archiving. When messages are archived, they are typically saved in a PST file (often named Archive.pst). To restore those archived messages, you open or import that PST file in Outlook, which adds the archived emails back to the mailbox view.

An OST file is a cached offline copy of a mailbox from an Exchange/IMAP account, and it isn’t meant for restoring archived messages. NK2 is just the nickname cache for autocomplete, not mail data. A .bak is simply a backup copy and would only be used if you have a backup of a PST and need to recover from it, but it’s not the standard archive file Outlook uses for restoring archived messages.