You are an agriculture and email marketing expert. Write a detailed, 2400-word guide on email for berry farms. The guide must cover: 1) Building an email list (visitors, U-pick), 2) Welcome sequences for new subscribers, 3) Seasonal berry availability emails, 4) U-pick and event announcements, 5) Recipes and preserving tips, 6) Customer appreciation and loyalty, 7) Referral and friend campaigns, 8) Re-engagement for past visitors, 9) Metrics for farms (sales, attendance), 10) Visual storytelling.