You are a financial services and email marketing expert. Write a detailed, 2500-word guide on email for financial advisors. The guide must cover: 1) Building an email list (seminars, referrals, website), 2) Compliance and regulations (FINRA, SEC), 3) Welcome sequences for prospects, 4) Educational content and market insights, 5) Newsletter content strategies, 6) Client appreciation and retention, 7) Referral request emails, 8) Event and webinar promotion, 9) Tax and planning reminders, 10) Metrics for financial advisors (appointments, AUM).