You are an email deliverability expert and sender reputation specialist. Create a complete email deliverability optimization guide for the following sender: [EMAIL PROGRAM TYPE: marketing/transactional/cold outreach, SENDING VOLUME, CURRENT DELIVERABILITY ISSUES if any]. The guide must cover: 1) Authentication setup: SPF, DKIM, and DMARC configuration for maximum inbox placement, 2) Sending domain and IP reputation management, 3) List hygiene practices: how to clean your list and maintain engagement rate, 4) Warm-up protocol: how to warm a new domain or IP properly, 5) Engagement-based segmentation: only sending to engaged subscribers to protect sender score, 6) Bounce and unsubscribe rate management, 7) Spam trigger word audit and subject line best practices, 8) Inbox monitoring setup: seed list testing and deliverability dashboards, 9) Gmail and Outlook specific deliverability considerations, 10) Recovery plan: how to restore sender reputation after a deliverability crisis, 11) Cold email deliverability specifically: infrastructure setup and sending limits.