Resend

Native integrations

Resend has documented guides for sending from Vercel Functions, Supabase Edge Functions, Cloudflare Workers, AWS Lambda and most web frameworks. It also integrates with Auth0 and works over SMTP with tools such as Customer.io, WordPress and Supabase Auth. Start by pointing your authentication emails at it, so sign-up and reset mail go through a verified domain.

API and webhooks

The REST API covers emails, batch sends, domains, contacts, segments, broadcasts, templates and API keys. Webhooks notify your app about events such as sent, bounced and complained, and inbound webhooks fire when mail arrives on a receiving domain. An idea: when a message bounces, mark the address as invalid in your database so your team stops sending to it.

MCP server

Resend has an official hosted MCP server, and you can also run it locally. It lets an AI client send emails, manage contacts, handle broadcasts and domains, and read inbound mail. An idea: ask an assistant to check yesterday's emails for bounces and list the addresses to clean up.

Built-in automation

Resend Automations start from custom events you send from your application, with steps for delays, conditions, waiting for an event and sending a template. An idea: send an event when a trial starts, wait two days, then send a templated onboarding email unless the user has already finished setup.