Curious Thunderbird "problem"... [View all]

I'll eventually check their boards and forums, but I'll ask here first.

I download all my email from seven accounts with Thunderbird and have almost no problems. I have noticed that if I delete an email from the T'bird inbox it also gets deleted from the server's inbox, but that's not a big deal.

The problem I just had was with one account that I'm closing and deleted all the emails from the server before moving all of them from T'bird's inbox to other folders. The ones I moved to folders were saved, but the ones in the T'bird inbox vanished along with the ones on the server.

Oops! Now that I know, I won't be this casual again, but I'd rather it not happen. At least it was just newsletters, not anything critical.

I couldn't find anything in the settings that might address this-- older versions had something about linking deletions to the server, but the latest one doesn't seem to.

Anyone have any ideas?