synchronize all imap folder in thunderbird

For various reasons, subfolders can get into the “not to sync” state in thunderbird 3.x. This is rather annoying as you will miss quite a lot messages, if you are e.g. using sieve mail filters on the remote imap server.

to turn that on do the following:

Edit – Preferences – Advanced – Config Editor – I’ll be careful, i promise!

Then enter


and set that to true (“Toggle”).