You are a design industry and email marketing expert. Write a detailed, 2400-word guide on email for architects and designers. The guide must cover: 1) Building an email list of potential clients, 2) Lead magnets (portfolio samples, design guides), 3) Welcome sequences for new leads, 4) Showcasing projects and case studies, 5) Educational content on design trends, 6) Newsletters with inspiration, 7) Event and webinar promotion, 8) Client appreciation and referral, 9) Metrics for creatives (inquiries, projects), 10) Visual design of emails.