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MailStream — Physical Mail MCP for AI Agents

Physical mail operations through MCP. MailStream is the first MCP server that lets AI agents send real postcards, letters, and manage direct mail campaigns. Operators can trigger physical mail from the same AI conversation where they're analyzing customer data.

What It Does for Operators

  • Send postcards — AI agents can trigger physical postcard sends to mailing lists
  • Send letters — Full letter mailing with templates and personalization
  • Campaign management — Create, manage, and track direct mail campaigns
  • List management — Upload and manage mailing lists
  • Agent-native — All direct mail operations through MCP tools

Installation

# No installation — hosted platform
# Sign up at mailstream.app, configure campaigns

Claude Desktop / Hermes Config

{
  "mcpServers": {
    "mailstream": {
      "type": "url",
      "url": "https://mailstream.app/developers/mcp-server"
    }
  }
}

Key Tools

Tool Description
send_postcard Send a physical postcard to a recipient or list
send_letter Send a physical letter with template
create_campaign Set up a new direct mail campaign
get_campaign_status Check delivery status and response rates
manage_lists Upload, clean, and segment mailing lists
estimate_cost Calculate postage and printing costs

Note: Tool names are approximate. Full documentation at mailstream.app.

Operator Use Cases

  1. Ecommerce Brands — Trigger "We miss you" postcards to lapsed customers from AI agent
  2. B2B Sales — Send personalized letters to high-value prospects after AI research
  3. Real Estate — Automated "Just Sold" postcards to neighborhoods
  4. Non-Profits — Thank-you letters triggered by donation events

CorpusIQ Angle

MailStream bridges the digital-physical gap for operators. A complete workflow: (1) CorpusIQ identifies lapsed customers from Shopify/Stripe data → (2) AI agent drafts personalized reactivation offer → (3) MailStream sends physical postcard → (4) CorpusIQ tracks revenue impact. Physical mail as an AI-native channel.

Limitations

  • US-only delivery (as of July 2026)
  • Physical mail has ~3-5 day delivery lag (not instant like email)
  • Per-piece costs (postage + printing)
  • Template design requires setup outside MCP