Resend review

Resend is a hosted email API with a SaaS app for managing contacts, campaigns and analytics. It sits between your application and recipient mail servers: your code calls Resend to send transactional or marketing email, and webhooks can notify your server when messages are delivered, opened, bounced or clicked. It is not a mail library you deploy as your delivery infrastructure.

The product combines API-based sending with contact management, a visual email editor, broadcast analytics and deliverability tools. Those tools include DNS monitoring, domain authentication, suppression lists and regional sending. React Email is a separate open-source component library that Resend promotes for building email templates; it does not make the Resend delivery service self-hosted.

This setup suits applications that want to keep delivery infrastructure outside their codebase while controlling sends through an API. It also puts delivery, contact workflows and campaign data in a vendor service, so teams should check their operational, retention and migration requirements before routing production mail through it.

The homepage shows an API call that creates a Resend client, sends an email with sender, recipient, subject and HTML fields, then handles either an error or a response ID. Resend lists SDKs for Node.js, Ruby, Python, PHP, Go, Rust, Java, Elixir and .NET. The integration surfaces also include REST, SMTP and a CLI; confirm the current language-specific setup and feature coverage in the vendor’s docs.

Test mode lets developers simulate events and experiment with the API without sending real email. Modular webhooks send server notifications for delivery, opens, bounces and link clicks, which gives an application an event path for updating its own records. The homepage links to documentation and shows React Email, an open-source component library for composing templates with React.

The wider SaaS app adds a visual editor, contact imports and broadcast analytics. Those features can reduce the need to build campaign workflows separately, but the core integration can remain API-driven. Teams should verify webhook event handling, retries and API rate limits in the docs before relying on them in production.

Resend’s Free plan costs $0 per month and includes 100 emails daily, three inboxes, three custom domains, 30-day data retention and five AI credits monthly. That can cover a small integration or a low-volume application, but the daily sending limit is the key ceiling for production traffic.

Pro and Scale have no daily sending limit in the listed plan details. Pro includes three inboxes, 10 custom domains, five webhook endpoints and 100 AI credits monthly; Scale includes three inboxes, 1,000 custom domains, 10 webhook endpoints and 500 AI credits monthly. Neither plan’s monthly price is published, and Enterprise pricing is also not published. Resend offers monthly billing only, with no annual discount.

Add-ons can affect the bill: 100 extra domains cost $20 monthly on Pro or Scale; Scale dedicated IPs cost $30 monthly and are available above 3,000 emails per day. Scale SSO costs $150 monthly, while Enterprise includes it. Additional inboxes cost $1 per inbox monthly on paid plans with pay-as-you-go enabled. Transactional overages are billed per 1,000 emails at the plan’s overage rate, which Resend does not publish.

Resend’s delivery product is presented as a hosted API and SaaS app, not as a self-hosted server. Resend does not publish source availability or a license for the delivery service on the vendor's site available here, so teams should not assume they can inspect or deploy the service themselves. React Email is identified separately as an open-source component library; that does not change the hosting model for Resend.

The vendor does not publish data-export details here. Ask how to export contacts, campaign data, suppression lists and event history before making Resend the system of record for those workflows. Migration is likely to center on replacing API calls and webhook handling, then moving the associated data and recreating domain and campaign configuration. Keeping email composition and delivery calls behind an internal interface can reduce the code changes if you later switch providers.

The Free plan’s 100-email daily limit and 30-day data retention matter if an application relies on it for production notifications. Paid plans remove the listed daily sending limit, but the vendor does not publish a rate-limit figure in the plan details. Confirm API limits, webhook behavior, retention and overage costs with Resend before estimating peak load or incident recovery.

Resend lists domain authentication, DNS monitoring, suppression lists, regional sending and managed dedicated IPs among its deliverability tools. The Scale dedicated IP add-on is available above 3,000 emails per day. The vendor's site does not establish compliance certifications or data-location terms, so organizations with specific requirements should ask the vendor directly.

Reddit feedback is mixed. Some developers praise the setup and API, while one thread includes reports of bugs and slow sending, including confirmation emails taking a minute or more. Those are individual reports, not a service-level guarantee or a representative reliability measure. Test delivery timing, bounce handling and operational support against your own requirements.