MCP.so
Sign In

MailStreamVerifiedFeatured

@Sponge Labs

HomepageDocumentation

About MailStream

The first MCP server for physical mail. Give any MCP-compatible AI agent the ability to send real postcards and letters, verify addresses, manage mailing lists and artwork, and track direct mail campaigns. Remote Streamable HTTP server with OAuth 2.1 sign-in (no API keys to paste) and 27 tools mirroring the MailStream REST API.

#direct mail#postcards#letters#marketing#physical mail#address verification

Connection details

https://my.mailstream.app/mcp

Setup

claude mcp add mailstream --transport http https://my.mailstream.app/mcp

Tools

No tools detected

Fetch the live tool list directly from this server's endpoint using the button above.

Overview

What is MailStream MCP?

MailStream is the first MCP server for physical mail. It gives any MCP-compatible AI agent (Claude, Cursor, VS Code, and more) the ability to send real postcards and letters, verify addresses, manage mailing lists and artwork, and track direct mail campaigns.

Key features

  • Send physical mail: postcards (4x6, 6x9, 6x11), letters, and radius mailer campaigns around any location
  • 27 tools mirroring the MailStream REST API v1
  • Address management: create, verify, and organize addresses and mailing lists; import from CSV
  • Artwork: supply designs by URL or HTML
  • Campaign control: track and cancel campaigns before dispatch
  • Built-in docs: searchable API documentation and product catalog exposed as MCP resources

Setup

Add to your MCP config:

{
  "mcpServers": {
    "mailstream": {
      "url": "https://my.mailstream.app/mcp"
    }
  }
}

Or in Claude Code:

claude mcp add --transport http mailstream https://my.mailstream.app/mcp

Sign in with OAuth when prompted. No API keys to copy.

Links

Frequently asked questions

What is the MailStream remote MCP server?

The MailStream remote MCP server is a hosted Model Context Protocol endpoint at https://my.mailstream.app/mcp, so AI assistants can connect to it without installing or running anything locally.

How do I connect to the MailStream MCP server?

Add the endpoint https://my.mailstream.app/mcp to any MCP-compatible client such as Claude Code, Cursor, or VS Code. The setup snippets on this page configure each client in one step.

Does the MailStream MCP server require authentication?

Yes. MailStream uses OAuth: the first time you connect, your MCP client opens a browser window to sign in and authorize access, then reuses the credentials for future sessions.

Which transport does the MailStream MCP server use?

MailStream exposes a Streamable HTTP endpoint, the transport used by remote MCP servers and supported by all major MCP clients.

Comments

Basic information

Transport

Streamable HTTP

Authentication

OAuth

Category

Communication

Author

Sponge Labs

Submitted by

Jeff Kingsford

More remote MCP servers

A

Attio

CRM records, notes, tasks

Airtable

Bring your structured data to Claude

Aiven

Model Context Protocol server for Aiven

A

Agent Utility MCP

Production remote MCP server with exactly 100 bounded tools: 85 paid tools and 15 free tools for text, JSON, encoding, identifiers, numbers, dates, URLs, validation, and secure web intelligence. Paid calls are charged on

B

B12

AI website generation