Five-tier email classification
Data443 · deciding on live customer mail
A mail server cannot wait. Every millisecond of classification is a millisecond of delivery latency for a real customer, so the budget was single-digit milliseconds, and an LLM call is three orders of magnitude too slow to sit in that path. The answer was to stop treating classification as one decision. Cheap deterministic checks resolve the overwhelming majority, and only genuinely ambiguous mail escalates to the ML classifier and an asynchronous LLM pass, which is what keeps both latency and GPU cost viable at this volume. False-positive and false-negative reports route back as retraining samples, so the model tracks real traffic rather than a frozen dataset.