Resend

Resend operates an email platform that lets developers send, receive, and manage emails programmatically - through a modern API rather than classic SMTP configuration.

Access is via REST endpoints or official SDKs across numerous programming languages, including Node.js, Python, PHP, Ruby, Go, Java, .NET, Rust, and Laravel. Core features include sending transactional emails such as welcome messages, password resets, and receipts, batch sending of up to 100 messages per request, and marketing email tools with contact and segment management plus automation flows. Inbound email can be processed via webhooks and MX records, while React Email provides a React-based template builder for email layouts. Domain verification and management of SPF, DKIM, and DMARC records round out the feature set.

For AI-assisted workflows, Resend offers an MCP server integration that lets email sending be controlled directly from AI agents and automation pipelines without manually wiring up the API.

The business model is usage-based with tiered plans for transactional and marketing emails, plus enterprise options with custom SLAs. Resend explicitly emphasizes responsible use: recipient opt-in is required, and unsolicited bulk sending is prohibited.

Resend was founded in 2023 and explicitly positions itself as a more developer-friendly alternative to older email APIs such as SendGrid or Mailgun, with a particular focus on modern developer experience and React-based email templates.