You can google it, you'll find many Mac OLM to Gmail Import Software. As I can see there are plenty of email migration software. This Tool provides functionality to split the oversized database into PST formation and massage filtering option is also available. Great feature that allows users to choose and use the smooth, selective conversion used to export items and folders from OLM to Gmail.[table][tr] [td]
https://www.kdetools.com/mac/olm/gmail/[/td][/tr][/table]
