Who Resend is
Resend is an email API for developers, based in San Francisco. It started in 2022 with an open source project and launched its sending platform in 2023, the year it joined Y Combinator, and its team also maintains React Email, an open source library for building emails as React components.
It covers account email and broadcasts to opted-in audiences, with SDKs for the common server languages and webhooks for every delivery event. That is why it is one of the email providers our notifications module connects to.
What it does in your platform
Notifications
Sends the platform's email from your verified domain: receipts, security alerts, statements and, for customers who opted in, broadcasts. Delivery events come back to the module as signed webhooks, so every message is tracked.
How the connection works
One connector in the notifications module talks to Resend's REST API. Your apps never hold the API key, and Resend's events reach the platform as webhooks signed with a secret only the platform knows.
A card is declined
The module picks the template your team edited in the backoffice, in the customer's language, to explain what happened.
Resend sends it
The module calls Resend's API from your verified domain, set up to send from Ireland when your customers are in Europe.
It is delivered
Resend hands the message to the customer's mail server and records whether it was delivered, delayed or bounced.
A signed webhook reports back
Each event arrives with an ID, a timestamp and a signature, which the platform checks with the webhook's signing secret.
The record is updated
The message's status changes in the backoffice, and a bounce or a spam complaint is recorded against the address.
Another route for alerts
If a critical message bounces or fails, the module sends it again through another channel.
Next to other providers
Resend can be your only email provider, or one of two: the module keeps a second provider standing by for critical messages, so a security alert still goes out if one of them has a problem.
Templates and preferences are kept in the platform rather than in Resend, so switching providers later is a configuration change, not a new app.
When Resend fits best
A strong fit when
- You want a simple API and signed webhooks, with SDKs for the common server languages.
- You write to customers in Europe, South America or Asia, and want mail sent from a region near them.
- You want broadcasts to opted-in customers from the same provider as your account email.
Also worth a look
- Mailgun, when message data must also be stored in the EU, not only sent from there.
- A provider your team already uses: its account becomes a connector too.
How we get you live
The contract
We help you get your Resend account and contract in place, set up for your markets.
Your domain and region
We add and verify your sending domain with you, with the DNS records Resend asks for, in the sending region that suits your customers.
The keys
The API key and the webhook signing secret go into your platform's secrets and nowhere else, so every event is proven to come from Resend.
A full test run
Every template goes first to Resend's test addresses, which simulate a delivery, a bounce and a spam complaint, then to your team's own inboxes before your first customer email.
