Did you use takeout to export your labels? <img src=https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/images/2024-10-27-03-09-20-7c525a.png> If not then you have a glorified copy of your all mail folder. Everything in one folder Then you tried to import an MBOX file as if it was a Thunderbird profile with inglorious results using both the import export tools and the native profile import. Lastly as you have apparently not configured any mail accounts, so your mail folders have not been built and showing on the left. Although you might want to click the ... beside new message button and see if the local folders account is hidden as I was not aware it was ever not present. The import export tools imports mbox files natively, not as a profile anything. The caveat of that is they only import to local folders and you have none to import to. Once you have local folder a right click (Or command click on some operating systems) will offer to import the mbox formatted file <img src=https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/images/2024-10-27-03-19-59-22b394.png> Fundamentally Thunderbird is an email client, not some sort of offline store for archived Gmails. So you are fighting the design nature of the application with your approach. .