I had no idea about how to open my NSF file in Lotus Notus. I can but say that SysInspire NSF viewer tool which is designed to open NSF files. I can assure you that this tool instantaneously accesses the NSF files database without looking at the NSF file size. Using the NSF viewer tool, I was able to get a  preview of the folders linked to the NSF file like the mails, contacts, journals, and calendars. Even the SysInspire is capable of splitting the pst files after conversion so that the file may not get corrupted.

I was facing problems opening the folders separately like the inbox, drafts, etc. but this SysInspire sorted out my trouble. Also, the older version still was easily able to open the NSF file.

Henceforth, I would also suggest you download the free version of the SysInspire and easily open the NSF file in Lotus Notes any version older or the latest ones.

This tool supports batch conversion also by which multiple files can be converted and then viewed by the user.

More info:-  NSF to PST Converter