If you want to open NSF file without Lotus Notes. You can not Open NSF file without Lotus Notes. First of download eSoftTools NSF to PST converter software and and convert NSF file to PST, MBOX, MSG, ICS, Yahoo, Gmail, Office 365, vCard, EMLX, HTML, EML and other formats in simple steps. After conversion you can easily open NSF file without Lotus Notes. Using the split option you can split a large PST file to multiple small files. And it has provided a recovery option where you can use the easily recovered NSF file in any Outlook format in some time.

Link - https://www.esofttools.com/blog/how-to-open-nsf-files-without-lotus-notes-free/