You are a nonprofit and email marketing automation expert. Write a detailed, 2400-word guide on behavioral triggers for nonprofits. The guide must cover: 1) Donation triggers (welcome, thank you), 2) Event registration triggers, 3) Volunteer signup triggers, 4) Advocacy action triggers, 5) Re-engagement for lapsed donors, 6) Setting up trigger-based sequences, 7) Personalization based on behavior, 8) Examples of nonprofit trigger emails, 9) Measuring impact on donations, 10) Compliance and privacy.