AgentSend MCP Skill for Claude

Claude is one of the most capable AI assistants available, but out of the box it cannot send or receive email. With AgentSend's MCP skill, you can give Claude full email capabilities: creating inboxes, sending messages, checking for incoming mail, and managing threaded conversations. No coding required. Just add a configuration block and Claude can handle email natively.

MCP (Model Context Protocol) is the open standard that connects AI models to external tools and data sources. AgentSend's MCP skill exposes email operations as MCP tools, making them available to Claude Desktop, Claude Code, and any MCP-compatible client. This guide covers setup, configuration, and practical examples of Claude handling email through MCP.

What Claude Can Do with AgentSend MCP

Once configured, Claude gains access to the following email operations:

• Create inboxes: Provision new email addresses on the fly. Each inbox gets a unique @agentsend.io address, or you can use a custom domain.
• Send email: Compose and send emails to any recipient. Claude can write the subject and body based on your instructions or context from the conversation.
• Receive email: Check an inbox for new messages and read their contents. Incoming emails are available immediately after delivery.
• Manage threads: Retrieve full conversation history for a thread, enabling Claude to compose context-aware replies that reference earlier messages.
• List inboxes: See all inboxes associated with your account, with their email addresses and message counts.

Setup: Claude Desktop

To add AgentSend to Claude Desktop, open your MCP configuration file and add the AgentSend skill:

{
  "mcpServers": {
    "agentsend": {
      "command": "npx",
      "args": ["@agentsend/mcp"],
      "env": {
        "AGENTSEND_API_KEY": "your_api_key_here"
      }
    }
  }
}

On macOS, this file is located at ~/Library/Application Support/Claude/claude_desktop_config.json. On Windows, it is at %APPDATA%\Claude\claude_desktop_config.json. Create the file if it does not exist.

After saving the config, restart Claude Desktop. You will see the AgentSend tools appear in Claude's tool list.

Setup: Claude Code

For Claude Code, add the MCP skill to your project's .mcp.json file:

{
  "mcpServers": {
    "agentsend": {
      "command": "npx",
      "args": ["@agentsend/mcp"],
      "env": {
        "AGENTSEND_API_KEY": "your_api_key_here"
      }
    }
  }
}

Claude Code will automatically detect the MCP configuration and make the email tools available in your session. You can also add it globally via your Claude Code settings.

Using Claude with Email

Once configured, you can ask Claude to handle email tasks naturally in conversation. Here are examples of what you can say:

Create an Inbox

"Create a new email inbox for handling customer support requests."

Claude will call the create_inbox tool and return the new inbox ID and email address. You can then share this address with customers or configure it as a support contact.

Send an Email

"Send an email to alice@example.com from inbox inbox_abc123.
Subject: Project Update.
Let her know the deployment completed successfully and
the new API endpoints are live."

Claude composes the full email body based on your instructions, calls send_message, and confirms the message was sent with the message ID and thread ID.

Check for New Messages

"Check inbox inbox_abc123 for new messages and summarize
any requests that need attention."

Claude retrieves recent messages, reads their contents, and provides a prioritized summary. You can then ask Claude to reply to specific messages, and it will use the correct thread ID to keep conversations grouped.

Reply to a Thread

"Get the full thread for thread_xyz789, then reply to the
customer explaining that their refund has been processed
and they should see it within 3-5 business days."

Claude reads the entire thread history for context, composes a reply that accounts for the full conversation, and sends it through AgentSend. The reply appears in the customer's email client as part of the existing thread.

Available MCP Tools

The AgentSend MCP skill exposes the following tools to Claude:

• create_inbox -- Create a new email inbox with an optional display name. Returns the inbox ID and email address.
• list_inboxes -- List all inboxes on your account with their addresses and message counts.
• send_message -- Send an email from a specified inbox. Supports threading via thread ID, plain text and HTML bodies, and recipient specification.
• get_messages -- Retrieve recent messages from an inbox. Returns sender, subject, body, and thread information.
• get_thread -- Get the complete message history for a specific thread, enabling context-aware replies.

Use Cases

With Claude and AgentSend MCP, you can build sophisticated email workflows without writing any code:

• Email triage: Have Claude check your inbox periodically, categorize messages by urgency, and draft replies for your review.
• Automated responses: Set up Claude to monitor an inbox and automatically reply to common questions using your knowledge base.
• Report distribution: Ask Claude to compile data from your conversation, format it as an email report, and send it to a distribution list.
• Follow-up management: Claude can track threads that need follow-up and send reminders when responses are overdue.

Security and Permissions

AgentSend's MCP skill respects Claude's permission model. Every email operation requires your explicit approval before execution. Claude will show you the tool call with all parameters (recipient, subject, body) and wait for your confirmation before sending. This ensures no email is sent without your knowledge.

Your API key is stored locally in the MCP configuration file and is never sent to Anthropic's servers. All email operations go directly from the MCP skill process to AgentSend's API.