Hello, After an upgrade to my most recent Mac I appear to have lost Thunderbird and all of my early backed up files (since deleted) from Gmail. Today, I reinstalled Thunderbird and linked it to Gmail. I then used Google Takeout to create an mbox folder and it worked fine. I now want to add this folder to Thunderbird as a separate backup which covers a particular period, say 2012 to today. After that I want to delete all of my mail - or at least everything up to 2019 so that I will have more space on my Gmail account. I tried the import function but it does not appear to show any way I can download a mail folder. I have read that I can simply shut down Thunderbird and copy the mbox file into the local folders in Thunderbird. So my first question is "can I simply transfer the mbox folder into Thunderbird local folders?" If so, may second question is "how can I find Thunderbird local folders on my MacBook Pro?" I have no idea where to find the Thunderbird folders. I have a recent MacBook Pro running Sonoma 14.4.1 I would be grateful for some help DanZ