I back-up my Thunderbird profile folder every week. I noticed that this week it was less than 50% of the size it was last week. Upon inspection this appeared to be due to the IMAP folders being much smaller this week. I had to wait for some of the email attachments, which I thought were stored locally, to download. After a while and after opening as many of these IMAP folders as I could, I checked the size of my profile folder again and it's now about 75% of the size it was last week. I'm a bit unsettled as the reason I use a desktop-based email client is to act as a temporary local backup for my webmail (IMAP) including email attachments until I get the time to sort through them... but it seems that many of the attachments have disappeared in the last few days (well, I can see them but if I want to open them I have to wait for them to download). I'm also a little concerned since my profile folder has shrunk to below 50% of what it was and then, in the last few hours has grown to 75% of what it was... Thunderbird did update itself in the last few days so I wonder whether this changed things? Things I've tried: 1) Opening & closing thunderbird a few times. 2) Rebooting whole desktop PC several times. 3) Checking Thunderbird's 'Synchronisation & Storage' settings (which seem to be as they should be if I want everything to be downloaded & stored locally)... I'm thinking of removing and then re-adding my webmail account to Thunderbird to see whether that will rest things a bit Any thoughts or suggestions?