Koltrix
Email API
Unicode in email: SMTPUTF8, encoded headers and IDNs
Non-ASCII names, subjects and addresses need different mechanisms. How RFC 2047 encoded words, SMTPUTF8 and IDN domains fit together in practice.
4 min read
Blog · Email API · page 3 of 3
Email API
Transactional email engineering: sending APIs, SMTP relays, webhooks, retries, idempotency, templates and testing.
Email APIPassword reset emails: token design and delivery checklist
Reset emails are a top account takeover vector. Design single-use, short-lived tokens, avoid account enumeration and make the email arrive fast.
4 min read
Email APIBuilding webhook consumers for retries and disorder
Webhooks arrive late, twice or out of order. Design consumers that acknowledge fast, deduplicate by event, process asynchronously and tolerate disorder.
4 min read
Email APIMagic links vs email OTP codes: speed and security
Passwordless login lives or dies on email delivery. Compare magic links and one-time codes on security, link scanners, latency and cross-device use.
5 min read