You must check the SysInspire NSF to PST Converter software provide by SysInspire Software. SysInspire Software has Much software which helps the user to convert, recover and migrate the important data of NSF, OST, PST, EDB and many more. Is it really required to use Outlook to open an NSF file? To use the Lotus Notes to Outlook Conversion tool to open a Lotus Notes NSF data file in Outlook, you must first convert it to a format that Outlook recognizes, such as PST and many more formats.