Koltrix
Email API
Queueing outbound email: why sends should be async
Sending email inside a web request couples your latency to someone else's SMTP server. A queue-based design with workers, retries and dead letters.
4 min read
Email APIObservability for email pipelines: logs, metrics, traces
Trace a message from API call to SMTP response. What to log, which metrics to emit and how to correlate IDs so 'did it send?' takes seconds.
4 min read
Email APISMTP relay vs HTTP API: how should your app send email?
SMTP relays are universally compatible; HTTP APIs are easier to make idempotent and observable. Compare them on errors, retries, security and speed.
4 min read