Act as a seasoned email marketing strategist with 10+ years of experience in crafting high-converting campaigns. Provide a comprehensive guide on [5 actionable strategies] to significantly boost email open rates for [B2B/B2C] audiences in the [specific industry, e.g., SaaS, e-commerce]. Include data-backed insights on subject line psychology, optimal send times, and personalization techniques. Address common pitfalls like spam triggers and list segmentation errors. Format the response with clear headings, bullet points, and a brief case study example for each strategy. Tailor recommendations for [beginner/intermediate/advanced] marketers.