📬 XTND | MCP | ONE

The Premier Model Context Protocol (MCP) Server for one.com Mail Infrastructure

Empower Claude, Cursor, ChatGPT, Zed, and autonomous AI agents with full mailbox intelligence (IMAP/SMTP) over one.com.

Features • Client Setup Guides • Tool Catalog • Workflow Prompts • Dynamic Resources • Architecture • Security

🚀 Key Features

• 📂 Complete Mailbox Hierarchy: Manage all standard and custom folders (INBOX, Drafts, Sent, Archive, Trash) with real-time total and unread message counters.
• 🔍 Server-Side Search Engine: Search by full-text keyword, sender, recipient, subject, date ranges, and flags (unread, flagged) without downloading gigabytes of data.
• 📖 AI Context Protection: Automatically converts HTML emails into clean, token-efficient Markdown, stripping tracking pixels, inline CSS blobs, and scripts.
• 🏷️ Triage & Flagging: Mark emails as read/unread/flagged, batch move between folders, and perform safe trash or permanent expunge.
• ✉️ Outbound SMTP Delivery: Send new messages via send.one.com:465 (implicit TLS), draft intelligent replies with automated In-Reply-To/References, forward threads, and manage drafts.
• ⚡ Triple-Transport Architecture:
  1. NPX Stdio for local desktop clients (npx @xtnd-dynamics/mcp-one).
  2. Streamable HTTP (/mcp) for Smithery, Cursor, and web AI agents.
  3. Server-Sent Events (/sse) for legacy streaming clients.

📦 Client Setup Guides

1. Claude Desktop (Local NPX)

Add the following to your claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "XTND | MCP | ONE": {
      "command": "npx",
      "args": ["-y", "@xtnd-dynamics/mcp-one"],
      "env": {
        "ONECOM_EMAIL": "[email protected]",
        "ONECOM_PASSWORD": "your_mailbox_password"
      }
    }
  }
}

2. 1-Click Install via Smithery CLI

npx -y @smithery/cli install @xtnd-dynamics/mcp-one --client claude

3. Cursor IDE (.cursor/mcp.json)

{
  "mcpServers": {
    "one-mail": {
      "command": "npx",
      "args": ["-y", "@xtnd-dynamics/mcp-one"],
      "env": {
        "ONECOM_EMAIL": "[email protected]",
        "ONECOM_PASSWORD": "your_mailbox_password"
      }
    }
  }
}

4. Zed Editor (settings.json)

{
  "context_servers": {
    "one-mail": {
      "command": {
        "path": "npx",
        "args": ["-y", "@xtnd-dynamics/mcp-one"],
        "env": {
          "ONECOM_EMAIL": "[email protected]",
          "ONECOM_PASSWORD": "your_mailbox_password"
        }
      }
    }
  }
}

5. Remote Hosted Edge Gateway (Streamable HTTP / SSE)

For web-based AI clients or SaaS deployments:

• Streamable HTTP Endpoint: https://one.mcp.xgi.io/mcp
• SSE Endpoint: https://one.mcp.xgi.io/sse

{
  "mcpServers": {
    "XTND | MCP | ONE": {
      "url": "https://one.mcp.xgi.io/mcp",
      "headers": {
        "X-OneCom-Email": "[email protected]",
        "X-OneCom-Password": "your_mailbox_password"
      }
    }
  }
}

🛠️ Tool Catalog (15 Tools)

| Tool Name | Description | Key Arguments | |---|---|---| | list_folders | List all mailboxes/folders with message and unread counts | (none) | | create_folder | Create a new mailbox folder | name (string) | | rename_folder | Rename an existing mailbox folder | oldName, newName | | delete_folder | Delete a mailbox folder | name (string) | | search_emails | Server-side filtered email search | folder, query, from, to, subject, unreadOnly, limit | | get_recent_emails | Retrieve recent email headers and envelope metadata | folder, limit | | get_email_content | Fetch full message body converted to Markdown | folder, uid, format | | get_email_thread | Retrieve full conversation thread history | folder, uidOrMessageId | | mark_emails | Update flags (read, unread, flag, unflag) | folder, uids, action | | move_emails | Move emails between folders (e.g. to Archive) | sourceFolder, targetFolder, uids | | delete_emails | Soft delete to Trash or permanent expunge | folder, uids, permanent | | send_email | Send outbound email via send.one.com:465 (TLS) | to, subject, bodyText, bodyHtml | | reply_email | Reply with automated headers and quotation | folder, uid, bodyText, replyAll | | forward_email | Forward email with original header context | folder, uid, to, comment | | create_draft | Save message draft directly to one.com Drafts | to, subject, bodyText |

🧠 Workflow Prompts (4 Assistants)

| Prompt Name | Purpose | Parameters | |---|---|---| | triage-inbox | Scans unread emails, categorizes into priority buckets, and drafts action plans | limit (optional) | | draft-reply | Inspects thread context and drafts contextual replies | uid (required), tone (optional) | | clean-inbox | Identifies marketing newsletters, promotional blasts, and automated alerts | folder (optional) | | executive-briefing | Generates a high-density daily digest with blocker checklist | (none) |

📂 MCP Resources (4 Endpoints)

| Resource URI | MIME Type | Description | |---|---|---| | one://folders | application/json | Real-time catalog of all mailboxes and unread counters | | one://status | application/json | Gateway connection health and protocol capabilities | | one://templates/meeting-followup | text/markdown | Standardized executive meeting summary template | | one://templates/out-of-office | text/markdown | Standardized out-of-office auto-reply template |

🏛️ Architecture

flowchart TD
    subgraph Clients ["AI Clients & Platforms"]
        CD["Claude Desktop"]
        CR["Cursor / Zed / Windsurf"]
        CG["ChatGPT Custom GPTs"]
        SM["Smithery Marketplace"]
    end

    subgraph LocalTransport ["Local Execution"]
        NPX["npx @xtnd-dynamics/mcp-one\n(Stdio Protocol)"]
    end

    subgraph EdgeTransport ["Cloudflare Edge (one.mcp.xgi.io)"]
        HTTP["Streamable HTTP (/mcp)"]
        SSE["Server-Sent Events (/sse)"]
        CARD["Static Server Card (/.well-known/mcp/server-card.json)"]
    end

    subgraph CoreEngine ["XTND Core Engine"]
        MIME["MIME & Markdown Token Optimizer"]
        IMAP["IMAP Client (imap.one.com:993 TLS)"]
        SMTP["SMTP Client (send.one.com:465 TLS)"]
    end

    subgraph OneCom ["One.com Mail Infrastructure"]
        MBOX["User Mailboxes & Folders"]
        MX["Mail Submission Relays"]
    end

    CD --> NPX
    CR --> NPX
    CR --> HTTP
    SM --> HTTP
    CG --> HTTP
    CD --> SSE

    NPX --> MIME
    HTTP --> MIME
    SSE --> MIME

    MIME --> IMAP
    MIME --> SMTP

    IMAP <--> MBOX
    SMTP --> MX

🔒 Security & AI Token Budgeting

• Zero-Credential Storage: Credentials are never persisted on edge servers. Stdio uses local process environment; hosted gateway uses ephemeral request headers.
• Implicit TLS Only: Inbound connections use port 993 (IMAPS) and outbound uses port 465 (SMTPS) over strict TLS sockets, avoiding STARTTLS vulnerabilities.
• Token Budget Guard: Incoming HTML is sanitized and converted to semantic Markdown, discarding CSS boilerplate, tracking pixels, and binary attachments to prevent context window exhaustion.

📄 License

MIT License © 2026 XTND Dynamics. Developed for the global AI developer ecosystem.