Email MCP Server

A Model Context Protocol (MCP) server built with C# .NET and MailKit that provides email tools.

Tools

Tool	Description
SendEmail	Send an email with optional attachments, CC/BCC, HTML body
ReadEmails	Read emails from any folder with pagination (JSON)
GetEmail	Get full email details including body
SearchEmails	Search by subject, sender, recipient, body, date, flags with pagination (JSON)
ReplyToEmail	Reply with threading headers, preserves original CC
ForwardEmail	Forward with original content inline
DownloadAttachments	Download attachments to a local directory
CreateDraft	Save a draft email with optional attachments
CreateFolder	Create an IMAP mailbox folder
DeleteFolder	Delete an IMAP mailbox folder
RenameFolder	Rename an IMAP mailbox folder
MoveToFolder	Move an email to a different folder
ListFolders	List all mailbox folders
MessageCounts	Get total and unread counts for a folder
AddFlags	Add flags to an email (Seen, Flagged, Deleted, etc.)
RemoveFlags	Remove flags from an email

Configuration

Edit EmailMcp/appsettings.json with your email credentials:

{
  "Email": {
    "SmtpHost": "smtp.example.com",
    "SmtpPort": 587,
    "ImapHost": "imap.example.com",
    "ImapPort": 993,
    "Username": "your-email@example.com",
    "Password": "your-password",
    "UseSsl": true
  }
}

Build & Run

cd EmailMcp
dotnet build
dotnet run

HTTP mode

dotnet run --project EmailMcp -- --http

The MCP endpoint will be available at http://localhost:5000/.

Stdio mode (default)

dotnet run --project EmailMcp

Docker

docker build -t email-mcp .
docker run -i email-mcp
# The -i flag is important since the MCP server communicates over stdio.

For HTTP mode:

docker run -p 5000:8080 email-mcp -- --http

To override settings, mount your own config:

docker run -i -v ./appsettings.json:/app/appsettings.json email-mcp

Docker Compose (with GreenMail for testing)

docker compose up -d

This starts:

• GreenMail – SMTP (port 3025) and IMAP (port 3143) test server
• email-mcp – MCP server in HTTP mode (port 5000)

Testing

# Run all tests
dotnet test

# Unit tests only
dotnet test --filter "Category!=Integration"

# Integration tests only (requires GreenMail running)
docker compose up -d
dotnet test --filter "Category=Integration"

Integration tests use EmailMcp.Tests/appsettings.test.json and automatically skip when the mail server is not reachable.

MCP Client Configuration

Add to your MCP client config (e.g. mcp.json):

{
  "mcpServers": {
    "email": {
      "command": "dotnet",
      "args": ["run", "--project", "/path/to/email-mcp/EmailMcp"]
    }
  }
}

VS Code:

{
  "servers": {
		"email-mcp": {
			"url": "http://127.0.0.1:5000/",
			"type": "http"
		}
	}
}

License

MIT