Teardown: the inbox that runs itself

The temptation is to point a model straight at Gmail. We didn't. Every inbound email is first normalised into a structured feed — sender class, thread history, attachments, extracted asks — so the triage layer reasons over clean data instead of raw HTML.

That one decision made everything downstream testable. You can replay a week of email through a rule change and diff the output.

Triage precision came from thirty plain-language rules the founder already had in their head — "supplier delays outrank new supplier pitches", "anything mentioning a refund is same-day".

The model's job is applying those rules to four hundred messy variations a day, not inventing judgement of its own. That's why precision landed at 92% and stayed there.

The deliverable was never "a sorted inbox". It was one ranked brief every morning — customers first, actions attached, everything else summarised into two lines.

The founder opens one document instead of three hundred threads. Same-day replies stopped being a goal and became the default.