I also secure mails that I receive via imap locally on the computer. Suppose I delete half the mails by mistake and then put the state of my backup back into the folders of Roaming/Thunderbird. The question is: does Google via Thunderbird load the restored mails back to the mail server (so mails saved) - or does it automatically delete everything again, like before - so half of the mails lost. Please info how it really is - because - depending on the answer - backing up locally stored Imap mails is actually nonsense. Thanks for your answer.