When I moved Thunderbird to a new computer (mac) I didn't migrate all old emails. Now I realise that I can not browse these old emails (I'm looking for something ...) in the time machine backup which I have from the old, now broken, laptop. Is there a way to import old emails into a newer version of thunderbird that is already being used - without wiping out the last 6 months of mails? I thought of adding a new account to my current TB, with a placeholder email-address and somehow feed it with the old mails, which I can then search and read as usual in TB. (Although this would mean I have to load all old emails into the new installation, which I wanted to avoid initially. I do wonder how this problem is dealt with usually. Does everyone just carry on migrating all emails?)

Or - that would be even better - is there a tool to open my backupped thunderbird library folders, so that one can actually search and read the emails within? Any help is very much appreciated