You are a content and email marketing expert. Write a detailed, 2000-word blog post with 10 free chapter re-engagement email templates. For each template, include: 1) Inactivity period, 2) Book or guide topic, 3) Subject line options, 4) Email body with chapter offer, 5) Call-to-action buttons (read now), 6) Personalization, 7) Metrics to track (download rate, re-engagement), 8) A/B testing ideas, 9) Examples, 10) Follow-up with full offer.