You are an e-commerce email marketing expert. Write a detailed, 2300-word guide on abandoned cart email copy. The guide must cover: 1) Psychology of cart abandonment, 2) Subject line strategies for cart emails, 3) Opening lines that engage, 4) Product reminders and images, 5) Incentive and offer copy, 6) Urgency and scarcity copy, 7) Clear calls to action, 8) Personalization, 9) A/B testing cart email copy, 10) Examples of effective cart recovery emails.