"Thundermail" will be part of a suite of Thunderbird Pro services, as the team behind the venerable Mozilla email client begins building a complete ecosystem.
Labels are displayed as folders on IMAP, which means that a single message could appear in multiple folders. Are there any other problems you're talking about?
One of the problems that annoyed me in the past is the complexity and ambiguity of deleting an email over IMAP. Depending on whether it's the last label of the deleted email, deleting an email from a label's directory either removes a label from this email, or actually deletes the email.
Please archive shit. It's OK to save old data, but not on the service. There are ways. Even banks, the most obsessive and legally strapped data hoarders keep their 5+ year old data in deep cold storage, away from the active services. 99.9^% of information that old won't be looked at by anyone.
It’s much easier to keep old data in active storage where it can be classified, searched, and have retention/deletion policies applied. Moving it elsewhere makes it more likely you’ll just hang onto it forever while not using it at all.
I don’t disagree that you should set up retention policies to delete old email, I disagree that you should remove old emails from primary service/storage.
I actually did need a 15 year old email a few months ago. I don’t recall what I needed, but I then set up a retention policy to delete old stuff.
Why not having an archive of exclusively warranties? Emails can be downloaded, indexed and compressed. I agree on keeping archives of old stuff. But emails used as cloud drives are a huge problem for IT and security reasons. A legal folder is better and facilitates backup, encryption and much more accessibility.
So you don't really want to archive in the technical sense, you want it offline for security, which is valid but extremely inconvenient for regular end users.