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3 articles tagged with email api.
Email API rate limits come in four layers - request rate, sending quota, SMTP concurrency, and receiving-ISP throttling - and each returns a different error. This guide covers reading rate-limit headers, which responses to retry and which never to, backoff with jitter, queue architecture, and separating transactional from bulk traffic.
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.
A transactional email is a one-to-one message triggered by a user action. Here is how it differs from marketing email, 16 examples to audit your product against, the SMTP ports and DNS records you need, and where promotional content crosses the line.
