Neil Brown on Nostr: If I want an offline mail store (local folder) in Thunderbird, kept in sync across ...

If I want an offline mail store (local folder) in Thunderbird, kept in sync across multiple machines via Nextcloud (and encrypted on the server via Cryptomator), it looks like I can use mbox but not maildir, which is rather annoying.

An IMAP server is likely the better answer, but it lacks the key thing I want: the email messages to be encrypted themselves (i.e. not disk encryption or transport encryption) on the server.

Thoughts from anyone who has tackled the same problem themselves very welcome!