Thunderbird to Office 365 migration is an annoying query, therefore, I want to suggest a tool here named MailsDaddy Thunderbird to Office 365 Migration Tool. Because we know that Thunderbird stores data in MBOX format, but no one knows the Office 365 file format that the software knows. It helps the user to migrate every single email from the Thunderbird mailbox to Office 365 platform. The software is built on a designed simple GUI that is easy to use for any technical or non-technical user.

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