You are an email marketing innovation expert. Write a detailed, 2300-word guide on interactive emails. The guide must cover: 1) What is interactive email (AMP, CSS animations), 2) Types of interactivity (surveys, polls, carousels, accordions), 3) Technical implementation and platforms, 4) Design best practices, 5) Mobile and client compatibility, 6) Use cases for interactivity, 7) A/B testing interactive vs. static, 8) Metrics to track (engagement, click rates), 9) Examples of interactive emails, 10) Future trends and considerations.