If you're looking for a free solution, you can try an easy manual trick. As Outlook doesn't support NSF format, so you can't directly export or import NSF database file into it. First you should save NSF file's data into such a file format which is supported by Outlook client. IBM Notes provides you two different formats into which you can save your NSF database files: Comma Separated Value and/or Structured Text. You can take a help of this blog post:- Export Lotus Notes Emails to MS Outlook