Resend

Resend is a transactional email service aimed at developers. The API is a single POST with an API key, and the platform's distinguishing feature is that templates can be written as React components rather than as HTML strings or a hosted drag-and-drop editor. The product covers the parts of email that are easy to get wrong: domain authentication with SPF, DKIM, and DMARC records; a broadcast product for marketing sends kept separate from transactional traffic; and webhooks for delivery, bounce, and complaint events. Sending is tracked per message so a support question about a specific email can be answered from the dashboard. Developers adopt it for the API ergonomics and the React template story. Teams with an existing marketing automation suite sometimes keep that for campaigns and use Resend only for the transactional path, since the two have different deliverability expectations and different unsubscribe rules.