How does Briar see a client's email?
Briar watches the inbox every minute — inbox and spam both, because carrier notices land in spam and matter anyway. Each message is classified by free rules first: sender, labels, whether the address is already on the book. A paid model call happens only when the answer is genuinely ambiguous.
Junk is filed without spending anything. A known client's message is never buried by a promotional signal, and when the rules and Google disagree about whether something is bulk, a local model breaks the tie from the sender and subject alone — never the body.
Proven on a real mailbox: 5,000 messages, 0 errors, 19 minutes.