I would like to recommend you to try
ZOOK NSF to PST Converter for the safe and flawless conversion of the NSF emails to PST format. It can smoothly convert all the
IBM Lotus Notes to MS Outlook PST file format. It is an independent solution that does not require the installation of any external utility to export the files format.
This utility supports all the versions of IBM Lotus Notes such as 9.0.1, 9.0, 8.5, 8.0, etc. The original hierarchy of the folders is kept intact throughout the conversion process. Moreover, this utility offers the users to export the batch files at once with all the data items included in it.
Learn more about this at:-
https://www.zooksoftware.com/nsf-to-pst/