Resend Pad

A minimal email utility to send emails using your Resend API key.

Send emails from your browser. No code, no accounts, no storage.

Overview

• Browser-Based UI: No installation. Open in any modern browser and start sending.
• CORS Proxy: Node.js backend handles API communication (Resend API doesn't accept browser requests directly).
• API Key Privacy: Your Resend API key is sent directly to Resend's API in request headers. Never stored, logged, or persisted on our servers.
• Open Source: Full source code visible. Self-host or audit the security yourself.
• Deploy Anywhere: Railway (easiest), Vercel, Netlify, or any server running Node.js.

Quick Start

Online (Railway Deployment)

Landing Page:  https://resendpad.up.railway.app/landing.html
Email Editor:  https://resendpad.up.railway.app/index.html

Local Development

# Terminal 1: Start the API proxy
node api-proxy.js

# Terminal 2: Open the app in browser
# Landing page: http://localhost:3001/landing.html
# Email editor: http://localhost:3001/index.html
# Or open index.html directly (auto-detects localhost:3001)

How It Works

1. Paste your API key into the form (stored only in browser memory)
2. Load your verified domains from Resend with "Load Domains" button (or enter From email manually)
3. Enter recipient email and subject
4. Compose your email using the Quill rich text editor with formatting toolbar
5. Click Send – your email is delivered via Resend immediately
6. Use Reset to clear all fields and start fresh (focus returns to editor for easy typing)

Features

• Rich Text Editor: Format emails with bold, italic, underline, headings, lists, links, code blocks, and clean formatting using Quill.js
• Domain Loader: Fetch verified sender domains directly from your Resend account with one click
• Reply Threading: Reply to existing email threads with proper Message-ID and References headers (Gmail/Outlook compatible)
• Reset Function: Clear all form fields and editor content with Reset button that properly returns focus to editor
• Batch Sending: Reuse form values – just change the recipient email for each send
• Clear Error Messages: Know exactly why a send failed (invalid domain, auth errors, etc.)
• Mobile Friendly: Works on desktop, tablet, and mobile browsers
• SEO Landing Page: Dedicated page at /landing.html to drive organic search traffic
• No Account Required: BYOK (Bring Your Own Key) – just paste your Resend API key
• Email-Optimized HTML: Automatically adds inline styles to fix spacing issues in Gmail/Outlook

Reply to Email Threads

New in v2.0: Reply to emails and keep them in the same conversation thread.

How it works:

1. Open the original email in Gmail
2. Click ⋮ (three dots) → Show original
3. Copy all text (Ctrl+A, Ctrl+C or Cmd+A, Cmd+C)
4. In Resend Pad, click "+ Show" under "Reply to Thread"
5. Paste into the text area and click "Extract & Auto-Fill"
6. The form automatically fills:
   • To field (sender's email)
   • Subject (with "Re: " prefix)
   • Threading headers (Message-ID, References)
7. Type your reply and send!

Your reply will appear in the same conversation thread for both you and the recipient.

Works with:

• ✅ Gmail
• ✅ Outlook / Office 365
• ✅ Apple Mail
• ✅ Thunderbird
• ✅ Most email clients that support RFC 2822 threading

Security

• Your API key never leaves your control – Sent directly to Resend's API in the Authorization header. We don't store, log, or persist it.
• No email content is logged – Email subject and body are forwarded to Resend and discarded. No database, no history, no backups.
• No user accounts or tracking – No sign-up, no login, no email collection, no analytics, no cookies.
• Transparent & auditable – Full source code on GitHub. Self-host if you want complete control.
• Stateless design – The proxy doesn't store anything. Restart the server and everything is cleared.

Requirements

• A modern web browser (Chrome, Firefox, Safari, Edge)
• A Resend account with an API key
• At least one verified domain in Resend (or manually entered verified domain)

Getting Your Resend API Key

1. Go to resend.com
2. Sign up or log in
3. Go to Settings → API Keys
4. Create a new API key with "Full Access" permissions
5. Copy and paste into Resend Pad

Note: "Sending Only" keys cannot list domains, but can send emails if you manually enter the From address.

Verified Domain Setup

1. In Resend dashboard, go to Domains
2. Add a new domain and verify ownership (DNS records)
3. Once verified, you can use that domain in Resend Pad

Deployment

Railway (Recommended - Easiest)

# Already deployed and live at:
# https://resendpad.up.railway.app

# To redeploy after changes:
railway up

How it works:

• Railway runs node api-proxy.js on the default PORT
• Frontend files served from root /:
  • index.html (email editor)
  • landing.html (SEO landing page)
  • sitemap.xml and robots.txt (SEO metadata)
• API calls proxied through /api/* endpoints
• Auto-detects production domain and routes accordingly

New to Railway? Deploy to Railway with referral – both of us get $5 credit.

Self-Hosted (Vercel, Netlify, own server)

# 1. Clone repo
git clone https://github.com/rozetyp/resend-email.git
cd resend-email

# 2. Deploy with your provider
# Vercel/Netlify: Connect repo, auto-deploys
# Own server: npm install && node api-proxy.js

# 3. App auto-detects environment
# - Local: uses http://localhost:3001
# - Production: uses your deployed domain

Local Development (No deployment)

# Just open index.html in your browser
# API calls will attempt localhost:3001
# Start proxy with: node api-proxy.js

Technical Stack

Frontend:

• HTML5 + Vanilla JavaScript (no frameworks)
• Tailwind CSS (CDN) for styling
• Quill.js for rich text editing (replaced Pell for better reliability)
• SEO-optimized landing page with comprehensive meta tags
• Favicon (inline SVG)
• Google Site Verification for Search Console

Backend:

• Node.js + native HTTP server
• Proxies requests to Resend API
• Serves static files (index.html, landing.html, sitemap.xml, robots.txt)
• Handles CORS automatically
• Auto-detects environment (localhost vs. production)

How the Proxy Works

Browser                    Your Server (api-proxy.js)       Resend API
  │                              │                              │
  ├─ POST /api/send ────────────>│                              │
  │  (with Bearer token)         ├─ POST /emails ──────────────>│
  │                              │  (with your API key)         │
  │                              │<─ 200 OK ────────────────────┤
  │<─ 200 OK ─────────────────────┤                              │
  │                              │                              │

Why a proxy?

• Resend API doesn't support CORS from browsers
• Proxy handles CORS transparently
• API key is passed through, never stored or logged
• Request status logged only (no email content, recipients, or subjects)

Privacy

This tool:

• ❌ Does NOT collect your personal data
• ❌ Does NOT log email content (only request status)
• ❌ Does NOT use analytics or trackers
• ✅ IS 100% open source
• ✅ CAN be self-hosted for complete privacy

API Key Safety:

• Your key is sent in HTTP headers only
• Never logged to disk in production
• Lost when container restarts (no persistence)
• You can rotate keys anytime in Resend dashboard

License

Open source. Use freely.

Support

Issues? Questions?

• Open an issue on GitHub
• Check the source code in index.html and api-proxy.js