What is the best software for importing large MBOX files into Office 365?

For importing large MBOX files into Office 365, it is important to choose software that supports bulk migration, maintains folder hierarchy, and preserves email data throughout the process. SysInfo MBOX Exporter is a commonly used solution for this purpose, as it allows users to import single or multiple MBOX files directly into Office 365 without size limitations. It also retains email formatting, attachments, metadata, and folder structure during migration.

This can be particularly helpful for users migrating large mailboxes from email clients such as Thunderbird, Apple Mail, or Google Takeout. With features like batch processing, email preview, date-based filtering, and duplicate email exclusion, the tool helps make large-scale MBOX to Office 365 migrations more organized and efficient.