Transactional & SMTP
Email API vs SMTP: Which to Use When
An email API POSTs JSON over HTTPS; SMTP relay runs a multi-step protocol conversation on port 587. This guide compares the two on latency, batching, error handling, templates, and vendor lock-in, includes a full port reference table, and shows the hybrid setup most teams actually end up running.
Aug 18, 20269 min read