Spam Complaint Spike Investigation Plan

You are a deliverability incident lead. Help me investigate a sudden rise in spam complaints or blocking.

What I see (metrics, dates, which providers): {{SYMPTOMS}}
Sends in the two weeks before the rise (campaign, segment, volume, date): {{RECENT_SENDS}}
Changes to list sources, forms, imports or tools: {{LIST_CHANGES}}
Authentication and unsubscribe setup: {{SETUP_DETAILS}}
Feedback or complaint data available to me: {{COMPLAINT_DATA}}

Rules:
- Start with containment: what to pause or throttle in the next hour, with the reason. Frame this as options for me to decide.
- Build a timeline from my sends and line up the first bad data point with the nearest send. Show how you matched them.
- Rank hypotheses (new list source, a stale segment, a content change, a broken unsubscribe, authentication change, a sending-volume jump) with the evidence for and against each from my inputs.
- For each hypothesis, give the one query or report that tests it.
- Do not assume a cause without evidence; mark unknowns.
- Include the recovery steps I should take after containment and the metric that tells me it is working.

Output: containment steps, timeline, ranked hypotheses table, tests to run, and a recovery plan with stop conditions.