Mail — Resend

A clean web app to send and manage email using the Resend API.

Features

• Compose emails with HTML or plain text body, CC, and Reply-To
• List sent emails with status badges and pagination
• View email details with safe HTML preview (sandboxed iframe)
• Settings drawer to configure your API key (stored in browser localStorage)
• Dark theme, responsive layout, keyboard accessible (Escape to close, focus-visible outlines)

Prerequisites

• Node.js 18+
• A Resend API key
• A verified domain for sending (e.g. example.com); or test with onboarding@resend.dev

Setup

# Install dependencies
npm install

# Copy env file and fill in your API key
cp .env.example .env

# Start the server
npm start

# Or with auto-restart on changes
npm run dev

Open http://localhost:3000.

Configuration (.env)

Variable	Description	Default
RESEND_API_KEY	Your Resend API key	—
RESEND_DEFAULT_FROM	Pre-filled From address in compose form	—
PORT	Server port	3000

Usage

1. Settings — Click the gear icon to enter your API key.
2. Compose — Fill in the form and click Send. The From address is remembered between sends.
3. Sent — Switch to the Sent tab to see your emails, their delivery status, and click any to view details.

API endpoints

Method	Path	Description
POST	/api/send	Send an email
GET	/api/emails	List sent emails (?limit=, ?after=)
GET	/api/emails/:id	Get email details
GET	/api/config	Get server configuration
GET	/api/status	Check if API key is configured

All endpoints accept x-api-key header for the Resend API key.

Security notes

• Never commit .env (it's in .gitignore).
• Email HTML is rendered in a sandboxed iframe to prevent XSS.
• The API key stays in localStorage on the client and is sent only via the x-api-key header.
• For production / multi-user use, add authentication and store keys server-side.