List Hygiene Monitor The ongoing hygiene watch, not the pre-flight — a scheduled read of list decay and suppression drift that turns the ESP export into a segmented re-permission / sunset / prune worklist . It cohorts the list by engagement recency (30/90/180/365-day last-open/click), trends hard-bounce and spam-complaint rates against benchmark and the prior baseline, and checks suppression-list growth and leakage — feeding the SEND S (Sender-integrity / Deliverability, list-hygiene sub-item) and E (Engagement, engagement-decay / sunset sub-item) signals. Scope guard: this skill produces the…