A field guide to
transactional email.
Practical guides, useful tools, and templates you can take with you. Built for the people behind the apps.
“Delivered” is only
part of the story.
Follow a missing message from the first API request to the receiving server—and find the next useful step.
Trace a missing email- Your applicationRequest saved
- Sending serviceQueued
- Receiving serverAccepted
- Recipient’s inboxStill to confirm
Server accepted does not mean inbox confirmed
Useful at every handoff.
All guides →8 guides · Practical answers, with examples
Delivered, but not in the inbox?
Trace a missing transactional email from API request to receiving server. A practical checklist for queues, bounces, spam, quarantine, and uncertain sends.
One email setup. Several apps.
Design a manageable email setup for multiple SaaS apps: project-specific keys, sending domains, Test and Live environments, webhooks, limits, and ownership.
Retry the request. Keep one email.
Use durable business events and idempotency keys to recover from email API timeouts. Includes a runnable no-send lab for lost responses and conflicting retries.
A better password reset email.
Download a free password reset email in HTML and plain text. Includes subject lines, fallback links, expiry copy, accessibility notes, and implementation checks.
Test the flow. Leave inboxes alone.
A practical testing strategy for email templates, API calls, retries, and webhooks. Includes a local mock server and clear limits on what simulation proves.
Make email authentication make sense.
Understand sending domains, SPF, DKIM selectors, and DMARC alignment with DNS commands, examples, and a practical troubleshooting sequence.
Your first email flow in Next.js.
Build a Next.js App Router email flow with a safe local fixture, stable request keys, server-side calls, error handling, and a message status lookup.
Build a webhook you can trust.
Verify signed email webhooks, commit events before acknowledging them, deduplicate retries, and preserve out-of-order observations. Includes a receiver and replay fixture.
A little help, right here.
All tools →Email header analyzer
Understand SPF, DKIM, and DMARC results. Your headers stay in your browser.
Sending-domain checker
Read the DNS setup guide while we prepare live domain checks.
Small emails.
Thoughtfully written.
Password resets, verification, receipts, and account updates. Start with clean HTML and plain text. No account needed.
Explore the template library