send-to-kindle-mcp

An MCP server that sends document files (EPUB, PDF, TXT, …) to your Kindle using Amazon's Send to Kindle email feature. The file is emailed as an attachment to your device's @kindle.com address.

Tool

send_to_kindle

| Argument | Type | Required | Description | | -------------- | ---------- | -------- | ----------- | | file_paths | string[] | yes | Absolute paths of the document files to send (1–25 files). | | kindle_email | string | no | Target @kindle.com address. Falls back to the KINDLE_EMAIL env var. |

All files are sent as attachments in a single email. Amazon's limits: up to 25 attachments and 50 MB combined per email.

Supported formats: .epub, .pdf, .txt, .rtf, .htm, .html, .png, .gif, .jpg, .jpeg, .bmp.

Prerequisites (do this once on Amazon's side)

Send to Kindle by email silently drops anything from an unapproved sender.

1. Find your Kindle address. Amazon → Manage Your Content and Devices → Devices → select your Kindle. It shows an address like [email protected].
2. Approve your sending email. Same page → Preferences → Personal Document Settings → Approved Personal Document E-mail List → Add a new approved e-mail address. Add the address you'll send from (your SMTP_FROM / SMTP_USER).

EPUB is supported natively (Amazon converts it to a Kindle format on receipt).

Install

No clone or build needed — the server runs via npx straight from npm:

npx @benbini/send-to-kindle-mcp

(Your MCP client launches it for you using the config below; you don't normally run this by hand.)

Gmail note

Use an App Password, not your account password: Google Account → Security → 2-Step Verification → App passwords. Host smtp.gmail.com, port 587.

Register with an MCP client

Claude Code

claude mcp add send-to-kindle \
  --env SMTP_HOST=smtp.gmail.com \
  --env SMTP_PORT=587 \
  --env [email protected] \
  --env SMTP_PASS=your-app-password \
  --env [email protected] \
  --env [email protected] \
  -- npx -y @benbini/send-to-kindle-mcp

Generic mcpServers JSON (Claude Desktop, Cursor, etc.)

{
  "mcpServers": {
    "send-to-kindle": {
      "command": "npx",
      "args": ["-y", "@benbini/send-to-kindle-mcp"],
      "env": {
        "SMTP_HOST": "smtp.gmail.com",
        "SMTP_PORT": "587",
        "SMTP_USER": "[email protected]",
        "SMTP_PASS": "your-app-password",
        "SMTP_FROM": "[email protected]",
        "KINDLE_EMAIL": "[email protected]"
      }
    }
  }
}

From source (development)

git clone https://github.com/BenjaminBini/send-to-kindle-mcp.git
cd send-to-kindle-mcp
npm install
npm run build

Then point your client's command/args at node /path/to/dist/index.js.

Environment variables

| Variable | Required | Default | Notes | | ------------- | -------- | ------------------------------- | ----- | | SMTP_HOST | yes | — | SMTP server hostname. | | SMTP_PORT | no | 587 | SMTP port. | | SMTP_SECURE | no | true if port 465, else false| Force TLS-on-connect. | | SMTP_USER | yes | — | SMTP username. | | SMTP_PASS | yes | — | SMTP password / app password. | | SMTP_FROM | no | SMTP_USER | From address; must be Amazon-approved. | | KINDLE_EMAIL| no | — | Default target if the tool arg is omitted. |

Troubleshooting

• Nothing arrives. Almost always the sender isn't on the approved list, or the Kindle address is wrong. Delivery can take a few minutes.
• SMTP auth fails. For Gmail/Outlook you need an app password with 2FA on.
• File rejected. Check every file is a supported format, that there are at most 25 of them, and that their combined size is under 50 MB.