Thanks for picking that up.

The developer suggests Control-Q for Ma users

Ma users? :-)

I use Mail Act-On, but a Mail plugin like this would make it convenient to quickly select less frequently accessed mailboxes out of the +400 under my nested IMAP hierarchies.

I’d really like to combine most of those mailboxes but still heavily rely on their names as a reminder of different senders/recipients and can easily find/browse messages with those groupings. I’ve considered using Smart Mailboxes instead, which would eliminate manual filing once they’re created. But there’s not enough match criteria (e.g. any header), plus performance could become intolerable and stability might suffer. I’m hoping MailTags will partially help when it officially supports IMAP. I’d rather be tagging messages than filing them.