How do I import Google Takeout MBOX data into Outlook Office 365?

If you are trying to import Google Takeout MBOX data into Outlook Office 365, first download your Gmail data using Google Takeout in MBOX format. Since Outlook 365 does not directly support MBOX files, you need an intermediate application like Mozilla Thunderbird. Configure your Office 365 email account in Thunderbird using IMAP settings. Next, install the ImportExportTools NG add-on in Thunderbird and import the downloaded MBOX files. After the import, drag the emails into your Office 365 mailbox folders within Thunderbird. The data will automatically sync with Outlook 365 online.
Alternatively, you can use professional migration tools such as Aryson MBOX to Office 365 Migration Tool for a faster and more reliable transfer. These tools support bulk migration, preserve folder hierarchy, and reduce the risk of data loss during the import process.