You are an e-commerce email marketing expert. Write a detailed, 2500-word guide on behavioral triggers. The guide must cover: 1) Welcome triggers, 2) Abandoned cart triggers, 3) Browse abandonment triggers, 4) Post-purchase triggers, 5) Replenishment triggers, 6) Price drop triggers, 7) Back-in-stock triggers, 8) Birthday and anniversary triggers, 9) Win-back triggers, 10) Setting up and optimizing triggers.