Does Thunderbird keep a local, accessible copy of whole accounts when using IMAP? Since the traditional way of using IMAP is by keeping the mails on the server and interacting with them via the server, I would think it doesn't.
Personally, I'm using nodejs-notify[1] to watch all mailboxes of all accounts via IMAP IDLE, and have it execute mbsync[2] when it receives an event to sync the account with a local Maildir. I got my MUA (mu4e[3]) configured to use those Maildirs without doing any IMAP itself.
Personally, I'm using nodejs-notify[1] to watch all mailboxes of all accounts via IMAP IDLE, and have it execute mbsync[2] when it receives an event to sync the account with a local Maildir. I got my MUA (mu4e[3]) configured to use those Maildirs without doing any IMAP itself.
[1] https://aur.archlinux.org/packages/nodejs-imapnotify/
[2] https://www.archlinux.org/packages/community/x86_64/isync/
[3] https://www.archlinux.org/packages/community/x86_64/mu/