The best email clients in 2026

"Top-reviewed email tools split between developer delivery infrastructure, power-user productivity, and team collaboration. Resend and peers emphasize APIs, SMTP, templates, webhooks, and deliverability controls for product emails, while Superhuman focuses on faster triage with shortcuts, AI drafting, and reminders. For shared customer-facing workflows, Missive stands out with shared inboxes, internal comments, assignments, and automation."