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io.github.pierre3/maildev-mcp

Official registry Productivity

MailDev MCP server. Manage Docker containers and inspect emails from your AI editor or MCP client.

Source code Documentation

What can you do with io.github.pierre3/maildev-mcp?

  • StartMaildev
  • GetEmail and ListEmails
  • WaitForEmail
  • VerifyAttachment

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NUGET package MailDevMcp
Claude Code 
claude mcp add maildev-mcp -e 'MAILDEV_API_PORT=<MAILDEV_API_PORT>' -- dnx MailDevMcp@1.0.1 --yes
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "maildev-mcp": {
            "command": "dnx",
            "args": [
                "MailDevMcp@1.0.1",
                "--yes"
            ],
            "env": {
                "MAILDEV_API_PORT": "<MAILDEV_API_PORT>"
            }
        }
    }
}

Environment variables

  • MAILDEV_API_PORT Port number for the MailDev REST API (default: 1080)

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Installation
  2. MCP Client Configuration
  3. Typical Workflow
  4. Available Tools
  5. Tool Behavior Notes
  6. Requirements and Assumptions
  7. Prerequisites
  8. Building from Source
  9. License

# MailDevMcp

English | 日本語

mcp-name: io.github.pierre3/maildev-mcp

An MCP (Model Context Protocol) server for MailDev.
Manage MailDev Docker containers and inspect received emails directly from your AI-powered editor or MCP client.

This server is intended for local development and test automation scenarios where an MCP client needs to:

  • start or stop a MailDev container
  • inspect inbox contents
  • wait for emails after triggering application behavior
  • inspect HTML bodies and attachments
  • verify attachment integrity byte-for-byte

Installation

Install as a global .NET tool:

dotnet tool install -g MailDevMcp

After installation, the maildev-mcp command becomes available.

MCP Client Configuration

Add the following to your MCP client settings (e.g. Claude Desktop, VS Code, etc.):

{
  "mcpServers": {
    "maildev-mcp": {
      "command": "maildev-mcp",
      "env": {
        "MAILDEV_API_PORT": "1080"
      }
    }
  }
}
Environment Variables
VariableDefaultDescription
MAILDEV_API_PORT1080Port number for the MailDev REST API

Typical Workflow

  1. Call StartMaildev to launch a local MailDev container
  2. Trigger your application to send an email
  3. Call WaitForEmail if delivery is asynchronous
  4. Use ListEmails, SearchEmails, or GetEmail to inspect the result
  5. Use GetEmailHtml, GetAttachmentContent, or VerifyAttachment when deeper validation is needed
  6. Clean up with DeleteEmail, DeleteAllEmails, or StopMaildev

Available Tools

ToolDescription
StartMaildevStart the MailDev Docker container with configurable SMTP port, API port, authentication, and TLS
StopMaildevStop and remove the MailDev Docker container
MaildevStatusCheck the running status of MailDev
ListEmailsRetrieve the list of received emails
GetEmailGet the details of an email by ID, including attachment information
GetEmailHtmlGet the HTML body of an email by ID
SearchEmailsSearch received emails by subject, sender, or recipient
DeleteEmailDelete a single email by ID
DeleteAllEmailsDelete all received emails
WaitForEmailWait until a new email matching given criteria arrives (useful for test automation)
GetAttachmentContentGet the raw Base64-encoded content of an email attachment
VerifyAttachmentVerify that an email attachment matches the original data by byte-by-byte comparison

Tool Behavior Notes

  • StartMaildev
    • Supports custom SMTP and API ports
    • Supports optional SMTP authentication
    • Treats empty or whitespace-only credentials as authentication disabled
    • Supports TLS with a generated self-signed certificate
  • GetEmail and ListEmails
    • Render missing or empty subjects as (no subject)
    • Render missing address lists as (none)
  • WaitForEmail
    • Polls MailDev until a matching email arrives or the timeout is reached
    • Reports transient MailDev connection failures in the returned message when they occur during polling
  • VerifyAttachment
    • Accepts a Base64-encoded original payload
    • Compares the received attachment byte-by-byte
    • Reports either exact match, size mismatch, or content mismatch

Requirements and Assumptions

  • Docker must be installed and available on the same machine where this MCP server runs
  • MailDev is accessed through its HTTP API on localhost
  • The configured API port in the MCP client must match the MailDev API port exposed by Docker

Prerequisites

Building from Source

git clone https://github.com/pierre3/MailDevMcp.git
cd MailDevMcp
dotnet pack -c Release
dotnet tool install -g --add-source ./bin/Release MailDevMcp

License

MIT

Frequently asked questions

What is io.github.pierre3/maildev-mcp?

MailDev MCP server. Manage Docker containers and inspect emails from your AI editor or MCP client.

How do I install io.github.pierre3/maildev-mcp?

It runs on your machine. In Claude Code: claude mcp add maildev-mcp -e 'MAILDEV_API_PORT=<MAILDEV_API_PORT>' -- dnx MailDevMcp@1.0.1 --yes. For other clients, paste the JSON configuration from this page into their MCP settings.

Does io.github.pierre3/maildev-mcp need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is io.github.pierre3/maildev-mcp open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains io.github.pierre3/maildev-mcp?

It is published by pierre3. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.