Please post more information, such as your email provider, POP or IMAP and server settings.

Server settings: imap.123-reg.co.uk port 993 default

Connection security: SSL/TLS Authentication: normal password

Server settings: I've unchecked three boxes about checking for new messages but it still is downloading anyway!

Local directory: C:\Users\Nick\AppData\Roaming\Thunderbird\Profiles\4sk8rim7.default-release\ImapMail\imap.123-reg.co.uk

Anything else?

You might try one or more of the settings in 'synchronization&storage'

Try to do what to one or more settings in 'synchronization&storage'.

Another point is that for some time Thunderbird has been telling me to 'Compact folders' but when I do, it says not enough disk space. I have cleared many gB from my hard drive but with no effect. Is it some other disk space? Help, about to end up with all broadband used up again! Can't stop the downloading even by closing Thunderbird.

If 'synchronize all messages' is clicked, change to 'synchronize the most recent' and pick a number of days.

Thanks. Done that. But will it just download endlessly the messages of the last 30 days?

Does it keep downloading the same messages? My thought was that limiting the days would stop the downloads.