The best email marketing tools to try in 2026

Top-reviewed email tools split into three lanes: developer-first delivery like Resend and Postmark for transactional flows, APIs, webhooks, and deliverability control; SaaS lifecycle platforms like Loops for combining product-triggered automation with marketing campaigns; and broader stacks that add templates, landing pages, outreach, or multichannel engagement for marketers, sales teams, creators, and communities.