There are many special converters for this but before using them check reviews about their level of security for your personal data. Unfortunately some of such converters can steal your data hidden and it's unacceptable for important mail. The good converter should be also simple in using and work fast with many files at the same time. For example, as the best ones in this case are considered Outlook Converter Software, Outlook Transfer and Outlook Import Tools. In case of online email conversion Email Migration Service convertemail.online/gmail-to-pst-conversion/ can be the nice choice too, comparing with other converters it can be used for free.