---
ref: tool:resend/send-email
name: Send an email
company: company:resend
workflows: []
access: [mcp, cli, api]
tags: [capability:send-email, category:email, has:api, has:cli, has:mcp]
docs: https://resend.com/docs/api-reference/emails/send-email
updated: 2026-09-27
---

# Send an email

Sends one email from a verified domain to up to 50 recipients, now or at a scheduled time, and returns its ID.

Pass `from`, `to`, `subject` and `html` or `text`, or a published `template`
with its variables. Send an `Idempotency-Key` header (`--idempotency-key` on
the CLI) so a retry never sends the email twice; keys expire after 24 hours.
`scheduled_at` takes an ISO 8601 time or plain words such as `in 1 min`.

## Set up

Use the first option your agent supports.

### MCP (official, remote)

Add this server to your agent's MCP settings, then sign in when asked.

```json
{ "mcpServers": { "resend": { "url": "https://mcp.resend.com/mcp" } } }
```

Call the MCP tool `send-email`.

Server URL: https://mcp.resend.com/mcp

### CLI (official)

Install the command, then confirm it runs.

```sh
npm install -g resend-cli
resend --version
```

Run `resend emails send`.

Set `$RESEND_API_KEY` in your environment first (get a key: https://resend.com/api-keys).

### API (official)

- Base URL: https://api.resend.com
- Endpoint: `POST /emails`
- Auth: send the header `Authorization: Bearer $RESEND_API_KEY`
- Get a key: https://resend.com/api-keys
- Docs: https://resend.com/docs/api-reference/introduction

Before doing anything else, make one read-only call to confirm access.

## Rules

- Ask the user before anything that sends messages, costs money, or changes data.
- Never print API keys.