You are an e-commerce email marketing expert. Write a detailed, 2300-word guide on abandoned cart emails. The guide must cover: 1) Psychology of cart abandonment, 2) Optimal timing for cart recovery emails, 3) Email 1: Reminder (gentle nudge), 4) Email 2: Incentive (discount, free shipping), 5) Email 3: Urgency (limited stock, countdown), 6) Subject line strategies, 7) Copywriting for cart emails, 8) Product images and details, 9) Mobile optimization, 10) A/B testing and optimization.