#5465 "One email per burst of alerts". When a switch reboots, every host's agent-offline rule fires at once and each account got one email per rule. Alert email now waits 30 s from the first alert: each recipient then gets one message listing every alert in the window, oldest first, in their own zone ("[Steward] 3 alerts: 2 firing, 1 resolved"). One alert alone keeps its usual email. Webhooks still post per alert, at once. Every alert's event records the email's outcome. A burst held when Steward stops is not sent; the alerts stay on the record and on the Alerts page. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>