If you are looking for a way to convert your EML files (created by any email client) into NSF format of IBM Lotus Notes, you can try SysInfoTools EML to NSF Converter tool. It can convert multiple EML files into NSF format at a time. It does not cause any damage or data loss to the original files while performing conversion action. The converter NSF file(s) can be saved at user-defined location. Demo of this tool is available for free evaluation.