Before a week ago, I was also searching for a method or solution to convert Lotus Notes to MBOX file format. But I was unable to find the solution. Then my colleague recommended me to try TransferMyMails Lotus Notes Converter software. It is very helpful and effective solution in converting NSF files from Lotus Notes to MBOX format. After that, I have used this program to save my NSF files in MBOX file. And trust me, it gives me an accurate result after completing the process.