Lotus Notes mailbox provides NSF files that users cannot import into Outlook PST format. Here some professional experience tool is required.
MailsDaddy NSF to PST Converter tool is the most popular and helpful utility to load and export data from NSF to PST format. It has several conversion options that allow the technical and nontechnical users to migrate mailbox from NSF to PST format. You can also test the free demo version of the software and migrate bulk data from NSF to Outlook PST format.
Read more: https://www.mailsdaddy.com/nsf-to-pst-converter/
More: https://readthedocs.org/projects/migrating-from-lotus-notes-to-outlook-with-nsf-to-pst-converter/