You are a seasonal agriculture and email marketing expert. Write a detailed, 2500-word guide on email for Christmas tree farms. The guide must cover: 1) Building an email list (visitors), 2) Pre-season announcements, 3) Seasonal promotions and events, 4) Tree care and tips, 5) Holiday cheer and stories, 6) Customer appreciation, 7) Referral and review requests, 8) Post-season follow-up, 9) Metrics for seasonal farms, 10) Year-round list building.