#5509 "Delivery you can see: each alert's email state in history, and outgoing email on Settings -> System" (milestone 501). - Alerts -> History: an alert's email reads from the outbox (#5506): "gathering" with when it sends, "sending", "retrying" with the attempt, next try and the server's last answer, "sent", or "failed" naming each reader it didn't reach and why (outbox.delivery / email_states). Events from before the outbox keep what they recorded. The Notified column shows once an alert has a queued email. - Settings -> System gets "Outgoing email": every email of the last 7 days not yet sent, failures first, then the longest retrying, with recipient, kind, state and last error, and a count of what was sent. Failures and anything still retrying after 5 minutes lead the page's verdict (outbox.outgoing). - get_alert_history (MCP) adds `email`: the same delivery state. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>