I wish Thunderbird could store folder settings on server, via IMAP Properties extension... It is only thing I miss in Thunderbird.

I'm not big fan of laptops, so I have three Thunderbird installations for one IMAP account: at my home workstation, my office workstation and on my neglected Laptop for rare business trips. And it is pain in the ss to setup identities, retention policies, columns visibility and order and such for each folder three times.

Yes, I have a lot of folders (about 100) as I'm subscribed to many mailing lists and sort my personal mail in different ways.

Filters could be configured only once, on server, thanks to Sieve, but all other settings must be repeated again and again.