Resend
Transactional email API built for developers, with React email templates.
Resend does one job well: sending transactional email from an app without fighting a legacy ESP dashboard. Templates are React components, the API is small, and deliverability tooling is visible rather than buried.
Domain verification with SPF, DKIM and DMARC is still on you — that, not the API, is what determines whether your mail reaches the inbox.
What it's genuinely good at
- Clean API with excellent docs
- React Email templates version-control nicely
- Free tier covers side projects
- Clear deliverability and bounce insights
Where it falls apart
- Marketing-campaign features are thin
- Free tier daily caps are low
- You still must configure DNS correctly
Alternatives to Resend
Who should use Resend
- Signup, OTP and receipt emails from an app
- Side projects needing reliable email fast
- Teams that want templates in the repo
What it costs
Free tier around 3,000 emails/month with daily caps; paid plans from about $20/month for 50,000 emails.
Frequently asked
Why do my emails go to spam?
Almost always missing or wrong SPF/DKIM/DMARC records, or sending from a brand-new domain with no reputation.
Can I send marketing campaigns?
Possible, but dedicated marketing platforms handle segmentation and unsubscribes far better.