If you want a professional method to migrate OST data to Gmail, you can use the EmailProHelp OST to PST Conversion Tool. It efficiently converts OST files to PST format, allowing users to recover emails, contacts, and other mailbox items. It’s easy to use, fast, and ensures data integrity while maintaining the original folder structure. Ideal for users needing to access or restore OST data without an Exchange Server connection. Works on all versions of Windows OS.

More Info: https://www.emailprohelp.com/blog/import-ost-file-into-gmail/