Resend

What it is

Resend is an email platform and REST API for sending transactional and marketing emails, as introduced in the Resend documentation and presented on the Resend homepage. Developers can write emails as React components with the open source react-email library. The platform provides SDKs, a way to test without sending real emails, and webhooks for real-time events, as presented on the homepage.

When it fits

Resend fits web applications that need programmatic email sending with domain authentication through SPF and DKIM, as described on the Resend homepage. It handles transactional emails sent through the /emails API and marketing broadcasts, which do not count against each other's limits, according to the Resend pricing page. The free-forever plan includes custom domains, and pay-as-you-go lets paid plans keep sending past their monthly quota at the plan's overage rate, per the same page.

What to watch

The API rate limit is set per team and is the same on every plan, so upgrading does not raise it, as explained on the Resend pricing page. Senders that hit the limit can use the Batch Email API, which sends up to 100 emails in one request. The free plan includes 3 custom domains, and sending from a separate domain for each brand requires the paid Domains add-on, per the same page.