Koltrix
Product
What happens after POST /api/v2/emails returns 202
Follow a Koltrix send from the 202 Accepted response through the queue, DKIM signing, SMTP delivery and the webhook events your app receives.
6 min read
Email APIDesigning a transactional email API you will not regret
Decisions that make an email-sending API pleasant for years: async acceptance, idempotency, explicit errors, stable fields and a clean event model.
4 min read
DeliverabilityTransactional vs marketing mail under bulk sender rules
Which bulk sender rules apply to receipts and password resets, which apply only to marketing, and why mixing both streams on one domain is risky.
4 min read
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 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