The easiest way to import MBOX files into a Google Workspace account is by using an email client like Mozilla Thunderbird with IMAP synchronization. I personally struggled with this process because I initially expected Google Workspace Gmail to support direct MBOX uploads, but there is no built-in option for that.
What worked for me was first connecting my Google Workspace Gmail account to Thunderbird using IMAP settings. After that, I used the ImportExportTools NG add-on to import the MBOX files into Thunderbird. Once the emails appeared, I simply dragged the folders into the synced Gmail mailbox folders. Thunderbird then automatically uploaded all emails to the Google Workspace account.
The manual method is manageable for smaller mailbox files, but it can become slow and confusing with large amounts of email data. To save time and avoid migration issues, I later switched to BLR MBOX Converter Tool, which made the entire process much easier while preserving attachments, folder hierarchy, and email formatting accurately.
What worked for me was first connecting my Google Workspace Gmail account to Thunderbird using IMAP settings. After that, I used the ImportExportTools NG add-on to import the MBOX files into Thunderbird. Once the emails appeared, I simply dragged the folders into the synced Gmail mailbox folders. Thunderbird then automatically uploaded all emails to the Google Workspace account.
The manual method is manageable for smaller mailbox files, but it can become slow and confusing with large amounts of email data. To save time and avoid migration issues, I later switched to BLR MBOX Converter Tool, which made the entire process much easier while preserving attachments, folder hierarchy, and email formatting accurately.