I am working to migrate a Gmail account from one account to another. I'm using Thunderbird as an intermediary step for this. Have installed the 45.1.1 version of TB of in on my Windows 10 machine just using the default IMAP setup. So far, so good, the emails have been pulled down from the Gmail account, folders setup as expected, etc. However, I'm not sure that all the emails have been pulled down yet. There are a lot of emails (almost 70,000 by the look of it). Have had the program running for days and still every now and then comes up with the message like 'downloading 1 of 9999 in All Mail'. How can I tell it's either got everything or otherwise force TB to just keep downloading everything? I'm a newbie to using TB, so any help here would be great :)