You are a sales and outreach copywriting expert. Write a detailed, 2200-word guide on cold email copy. The guide must cover: 1) Researching the recipient for personalization, 2) Crafting a compelling subject line, 3) Opening with a hook that grabs attention, 4) Demonstrating value and relevance, 5) Making a clear and specific ask, 6) Keeping the email concise and scannable, 7) Including social proof or common ground, 8) Optimizing for mobile reading, 9) Following up effectively (without being annoying), 10) Measuring open and reply rates.