Tutorials

8 posts on tutorials for AI agents that send and receive email.

30 July 2026 · 4 min read

Send a newsletter from your own app

Storing your own list and sending a broadcast from your own code, with the consent, unsubscribe and reputation parts that a loop over your users table gets wrong.

30 July 2026 · 4 min read

How to migrate from SendGrid without changing your code

emails.sh serves SendGrid's v3 mail/send wire format, personalizations and all. Two lines of configuration in Node, one in every other language, and the order matters.

28 July 2026 · 4 min read

How to send email in Next.js with the App Router

A complete Next.js App Router email setup: a Server Action, a route handler, where the API key lives, and the runtime mistakes that break it in production.

3 July 2026 · 4 min read

Why nodemailer does not work on Vercel

SMTP from a serverless function fails for reasons that have nothing to do with your code. Here is what actually happens, and the HTTPS fix that ends it.

12 June 2026 · 4 min read

Custom email for Supabase Auth

Replace Supabase's built-in auth mail with your own sender, either through custom SMTP or a Send Email Auth Hook, and keep the token generation Supabase does for you.

5 June 2026 · 4 min read

Custom SMTP and custom email delivery in Clerk

Send Clerk's auth email from your own domain: what custom SMTP covers, when to take delivery over with a webhook, and the code for both paths.

15 May 2026 · 5 min read

Building an email verification flow that actually works

Token design, expiry, resend limits, the race conditions nobody tests, and the copy that keeps people from giving up. A complete verification flow, end to end.

1 May 2026 · 4 min read

Sending email from Cloudflare Workers, with no SMTP and no sockets

Workers cannot open an SMTP connection, so every mail library fails there. What actually works: an HTTPS API, secrets via wrangler, queues, and cron triggers.