If you're looking to bulk import MBOX files into Gmail, the BitRecover MBOX to Gmail Wizard is a reliable and efficient solution.This tool is specifically designed to handle large-scale migrations, allowing you to import multiple MBOX files into your Gmail account seamlessly. With its user-friendly interface, you can easily upload MBOX files, apply filters if needed, and map the data to your Gmail account. The wizard ensures that all email attributes—like subject, sender, recipient, attachments, and timestamps—are preserved during the migration.
Shoviv IMAP Backup and Restore tool facilitates the import of MBOX files into Gmail. To begin, install and run the Shoviv wizard, then select the "Restore/Export" option. Choose MBOX as the file format and create a restore job. Next, map the MBOX file to the Gmail mailbox, validate, and apply filters as needed. The tool also offers options for data filtration and incremental export.
Read more - https://www.shoviv.com/blog/import-mbox-to-gmail-with-or-without-thunderbird/