#api
Transactional Email API: How to Send Reliable App Email in 2026
What a transactional email API actually does, how to choose one, and a copy-paste example for sending your first message in minutes.
Choosing an SMTP Relay Service: What Actually Matters
When to use an SMTP relay vs an API, what to look for, and how to migrate without breaking your existing app.
Email API vs SMTP: Which Should Your App Use?
A clear comparison of sending email over an HTTP API versus SMTP — speed, features, reliability and when to pick each.
Email Webhooks: React to Delivered, Bounced and Opened in Real Time
What email webhooks are, the events worth subscribing to, and how to handle them reliably in your app.
Integrating an Email API: A Practical Checklist
Everything to get right when you integrate an email API — keys, retries, webhooks, suppression and testing — in one checklist.
Keeping Your Email API Key Secure
Practical rules for storing, scoping and rotating email API keys so a leak never becomes a spam incident.
Free Email API: What You Get and Where the Limits Are
What a free email API tier realistically includes, what to watch for, and how to know when to upgrade.