Mailsnail MCP

Mailsnail is an MCP server that enables AI agents to send physical mail, including letters and certified mail, via USPS. It supports managed mode with prepaid balances or self-hosted mode using Click2Mail or Lob accounts. Key tools include preview_letter, send_letter, verify_address, and get_letter for tracking.

Visit Mailsnail

Package and access

Local package with source-attributed installation metadata. Koskamo does not execute packages during review.

Community listingLocal stdioSource reviewed; not executedPublished by Mailsnail

Vendor documentation

What you can do with it

Send physical thank-you notes or personal postcards
Mail legal notices and certified compliance mail
Verify US addresses before sending
Track delivery status of sent letters

Source and maintenance

Community listingRegistry 0.6.0MIT

mcp-registry: io.github.iancollins27/mailsnail@0.6.0 Source repository Project website

Last repository push: Oct 19, 2026, 9:06 PM UTC
Maintenance checked: Nov 2, 2026, 5:07 PM UTC

Packages and installation

Source-provided package data. Koskamo has not executed or live-probed this package.

mailsnail 0.6.0

npm

mailsnail package definition

{
  "version": "0.6.0",
  "transport": "stdio",
  "identifier": "mailsnail",
  "registryType": "npm",
  "registryBaseUrl": "https://registry.npmjs.org",
  "environmentVariables": [
    {
      "name": "MAIL_PROVIDER",
      "default": "managed",
      "isRequired": true,
      "description": "Where to mail from: 'managed' (default, no signup, pay-per-piece via Stripe), 'click2mail' (BYO account), or 'lob' (BYO key)."
    },
    {
      "name": "MAIL_API_BASE_URL",
      "default": "https://api.mailsnail.dev",
      "description": "Hosted Mailsnail backend. Required when MAIL_PROVIDER=managed."
    },
    {
      "name": "CLICK2MAIL_USERNAME",
      "description": "Click2Mail account username. Required when MAIL_PROVIDER=click2mail."
    },
    {
      "name": "CLICK2MAIL_PASSWORD",
      "description": "Click2Mail account password. Required when MAIL_PROVIDER=click2mail."
    },
    {
      "name": "LOB_API_KEY",
      "description": "Lob API key. Required when MAIL_PROVIDER=lob. test_* is free; live_* actually mails."
    },
    {
      "name": "MAIL_MCP_ALLOW_LIVE",
      "default": "0",
      "description": "Set to '1' to actually mail in BYOK modes. Default '0' is dry-run."
    },
    {
      "name": "MAIL_MCP_SPEND_CAP_USD",
      "default": "25",
      "description": "Per-session estimated spend cap. Server refuses sends past this."
    }
  ]
}

Tools

Reported by the attributed source; not independently observed by Koskamo.

No tool definitions available.

Maintenance history

Public check and source-refresh events. Editorial and ownership records remain private.

Nov 2, 2026, 5:07 PM UTC · repository · passed · metadata changed · updated
Nov 2, 2026, 5:07 PM UTC · backfill · recorded · Pre-expansion baseline; unobserved rich metadata remains unknown

Connect from your client

Each snippet configures the same source-provided package; replace placeholders before use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Cursor

Merge this local stdio configuration, replace every placeholder environment value, and restart Cursor. Koskamo has not executed this package.

Cursor configuration

{
  "mcpServers": {
    "mailsnail-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "mailsnail@0.6.0"
      ],
      "env": {
        "MAIL_PROVIDER": "<YOUR_MAIL_PROVIDER>",
        "MAIL_API_BASE_URL": "<YOUR_MAIL_API_BASE_URL>",
        "CLICK2MAIL_USERNAME": "<YOUR_CLICK2MAIL_USERNAME>",
        "CLICK2MAIL_PASSWORD": "<YOUR_CLICK2MAIL_PASSWORD>",
        "LOB_API_KEY": "<YOUR_LOB_API_KEY>",
        "MAIL_MCP_ALLOW_LIVE": "<YOUR_MAIL_MCP_ALLOW_LIVE>",
        "MAIL_MCP_SPEND_CAP_USD": "<YOUR_MAIL_MCP_SPEND_CAP_USD>"
      }
    }
  }
}

Cline

Merge this local stdio configuration, replace every placeholder environment value, and restart Cline. Koskamo has not executed this package.

Cline configuration

{
  "mcpServers": {
    "mailsnail-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "mailsnail@0.6.0"
      ],
      "env": {
        "MAIL_PROVIDER": "<YOUR_MAIL_PROVIDER>",
        "MAIL_API_BASE_URL": "<YOUR_MAIL_API_BASE_URL>",
        "CLICK2MAIL_USERNAME": "<YOUR_CLICK2MAIL_USERNAME>",
        "CLICK2MAIL_PASSWORD": "<YOUR_CLICK2MAIL_PASSWORD>",
        "LOB_API_KEY": "<YOUR_LOB_API_KEY>",
        "MAIL_MCP_ALLOW_LIVE": "<YOUR_MAIL_MCP_ALLOW_LIVE>",
        "MAIL_MCP_SPEND_CAP_USD": "<YOUR_MAIL_MCP_SPEND_CAP_USD>"
      }
    }
  }
}

VS Code

Merge this local stdio configuration, replace every placeholder environment value, and restart VS Code. Koskamo has not executed this package.

VS Code configuration

{
  "servers": {
    "mailsnail-mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mailsnail@0.6.0"
      ],
      "env": {
        "MAIL_PROVIDER": "<YOUR_MAIL_PROVIDER>",
        "MAIL_API_BASE_URL": "<YOUR_MAIL_API_BASE_URL>",
        "CLICK2MAIL_USERNAME": "<YOUR_CLICK2MAIL_USERNAME>",
        "CLICK2MAIL_PASSWORD": "<YOUR_CLICK2MAIL_PASSWORD>",
        "LOB_API_KEY": "<YOUR_LOB_API_KEY>",
        "MAIL_MCP_ALLOW_LIVE": "<YOUR_MAIL_MCP_ALLOW_LIVE>",
        "MAIL_MCP_SPEND_CAP_USD": "<YOUR_MAIL_MCP_SPEND_CAP_USD>"
      }
    }
  }
}

Claude Desktop

Merge this local stdio configuration, replace every placeholder environment value, and restart Claude Desktop. Koskamo has not executed this package.

Claude Desktop configuration

{
  "mcpServers": {
    "mailsnail-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "mailsnail@0.6.0"
      ],
      "env": {
        "MAIL_PROVIDER": "<YOUR_MAIL_PROVIDER>",
        "MAIL_API_BASE_URL": "<YOUR_MAIL_API_BASE_URL>",
        "CLICK2MAIL_USERNAME": "<YOUR_CLICK2MAIL_USERNAME>",
        "CLICK2MAIL_PASSWORD": "<YOUR_CLICK2MAIL_PASSWORD>",
        "LOB_API_KEY": "<YOUR_LOB_API_KEY>",
        "MAIL_MCP_ALLOW_LIVE": "<YOUR_MAIL_MCP_ALLOW_LIVE>",
        "MAIL_MCP_SPEND_CAP_USD": "<YOUR_MAIL_MCP_SPEND_CAP_USD>"
      }
    }
  }
}

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