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martinzarfl

Mail MCP Server

by martinzarfl
README.md
# Mail MCP Server

A Model Context Protocol (MCP) server for SMTP and IMAP-based email handling. This server enables AI assistants to send and read emails, manage mailboxes, and handle email configurations securely.

## Features

### Sending Emails (SMTP)
- **Send Emails**: Send emails with HTML/plain text content, attachments, and CC/BCC support
- **Connection Verification**: Test SMTP connection and authentication
- **Configuration Testing**: Test custom SMTP configurations without modifying server settings

### Reading Emails (IMAP)

- **Fetch Emails**: Retrieve emails from any mailbox with filtering options
- **Search Emails**: Simple search by subject, sender, or content
- **Advanced Search**: Complex queries with multiple criteria (sender, recipient, date range, size, flags)
- **List Mailboxes**: Browse all available folders/mailboxes
- **Mark Emails**: Mark emails as read/unread or flagged/unflagged

### Email Organization

- **Create/Delete Mailboxes**: Manage folder structure
- **Move Messages**: Organize emails between folders
- **Copy Messages**: Duplicate emails to multiple folders
- **Save Drafts**: Store draft emails for later editing

### Advanced Features

- **Thread View**: Get entire conversation threads with chronological ordering
- **Download Attachments**: Retrieve specific attachments with base64 encoding
- **Message Relationships**: Track reply chains via Message-ID, In-Reply-To, and References headers

### Security

- **Secure**: All credentials managed via environment variables
- **TLS Support**: Encrypted connections for both SMTP and IMAP

## Installation

```bash
npm install
npm run build
```

## Configuration

### Required Environment Variables

```bash
# SMTP Configuration (for sending emails)
export SMTP_HOST="smtp.gmail.com"          # SMTP server hostname
export SMTP_PORT="587"                      # SMTP server port (587 or 465)
export SMTP_USER="your-email@gmail.com"    # SMTP username
export SMTP_PASS="your-app-password"       # SMTP password
export SMTP_FROM="your-email@gmail.com"    # (Optional) Default sender address
export SMTP_SECURE="false"                 # (Optional) Use TLS (true for port 465)
```

### Optional IMAP Configuration (for reading emails)

If not provided, IMAP settings default to SMTP values:

```bash
export IMAP_HOST="imap.gmail.com"          # IMAP server (defaults to SMTP_HOST)
export IMAP_PORT="993"                      # IMAP port (default: 993)
export IMAP_USER="your-email@gmail.com"    # IMAP username (defaults to SMTP_USER)
export IMAP_PASS="your-app-password"       # IMAP password (defaults to SMTP_PASS)
export IMAP_TLS="true"                     # Use TLS (default: true)
```

## Usage

### Running the Server

#### Stdio Transport (Default)

For use with Claude Desktop or other stdio-based clients:

```bash
# Without .env
npm run dev

# With .env file
npm run dev:env
```

#### SSE Transport (HTTP/Server-Sent Events)

For web-based clients or remote connections:

```bash
# Start SSE server on port 3000
TRANSPORT=sse npm run dev:sse:env

# Or custom port
TRANSPORT=sse PORT=8080 npm run dev:sse:env
```

The server will be available at:

- **MCP endpoint**: `http://localhost:3000/mcp`
- **SSE endpoint**: `http://localhost:3000/sse`

**Environment Variables for SSE:**

- `TRANSPORT=sse` - Enable SSE transport
- `PORT=3000` - HTTP server port (default: 3000)
- `SSE_PATH=/sse` - SSE endpoint path (default: /sse)

### Using with Claude Desktop (Stdio)

Add to your Claude Desktop configuration file:

**macOS**: `~/Library/Application Support/Claude/claude_desktop_config.json`

**Windows**: `%APPDATA%\Claude\claude_desktop_config.json`

```json
{
  "mcpServers": {
    "mail": {
      "command": "npx",
      "args": ["-y", "martinzarfl/mail-mcp"],
      "env": {
        "SMTP_HOST": "smtp.provider.com",
        "SMTP_PORT": "587",
        "SMTP_USER": "your-email@provider.com",
        "SMTP_PASS": "your-mail-password",
        "SMTP_FROM": "your-email@provider.com",
        "IMAP_HOST": "imap.provider.com",
        "IMAP_PORT": "993",
        "IMAP_USER": "your-email@provider.com",
        "IMAP_PASS": "your-mail-password"
      }
    }
  }
}
```

## Available Tools

### SMTP Tools (Sending Emails)

#### send_email

Send an email via SMTP.

**Parameters:**

- `to` (required): Recipient email address
- `subject` (required): Email subject line
- `text` (optional): Plain text email body
- `html` (optional): HTML email body
- `from` (optional): Sender email address (uses SMTP_FROM if not provided)
- `cc` (optional): CC recipient email address
- `bcc` (optional): BCC recipient email address
- `attachments` (optional): Array of attachments with `filename`, `content`, and `encoding` (base64 or utf-8)

**Example:**

```typescript
{
  "to": "recipient@example.com",
  "subject": "Hello from MCP",
  "text": "This is a test email",
  "html": "<h1>This is a test email</h1>"
}
```

#### verify_connection

Verify the SMTP connection and authentication using configured credentials.

**Parameters:** None

#### test_smtp_config

Test SMTP configuration with custom credentials without modifying the server configuration.

**Parameters:**

- `host` (required): SMTP server hostname
- `port` (required): SMTP server port
- `user` (required): SMTP authentication username
- `password` (required): SMTP authentication password
- `secure` (optional): Use TLS (default: true for port 465)

#### get_smtp_info

Get information about the current SMTP configuration (without revealing credentials).

**Parameters:** None

### IMAP Tools (Reading Emails)

#### list_mailboxes

List all available mailboxes/folders in the IMAP account.

**Parameters:** None

**Example Response:**

```json
{
  "success": true,
  "mailboxes": [
    {"name": "INBOX", "delimiter": "/", "children": 0},
    {"name": "Sent", "delimiter": "/", "children": 0},
    {"name": "Drafts", "delimiter": "/", "children": 0}
  ],
  "count": 3
}
```

#### fetch_emails

Fetch emails from a specific mailbox with optional filters.

**Parameters:**

- `mailbox` (optional): Mailbox name (default: "INBOX")
- `limit` (optional): Maximum emails to fetch, 1-100 (default: 10)
- `unseen` (optional): Only fetch unread emails (default: false)
- `since` (optional): Only fetch emails since date (ISO 8601 format)

**Example:**

```typescript
{
  "mailbox": "INBOX",
  "limit": 5,
  "unseen": true
}
```

#### search_emails

Search for emails in a mailbox by subject, sender, or content.

**Parameters:**

- `mailbox` (optional): Mailbox name (default: "INBOX")
- `query` (required): Search query string
- `limit` (optional): Maximum results, 1-100 (default: 10)

**Example:**

```typescript
{
  "query": "meeting",
  "limit": 10
}
```

#### mark_email

Mark an email with a specific flag.

**Parameters:**

- `mailbox` (optional): Mailbox name (default: "INBOX")
- `uid` (required): Email UID to mark
- `flag` (required): Flag to set ("read", "unread", "flagged", "unflagged")

**Example:**

```typescript
{
  "uid": 123,
  "flag": "read"
}
```

### Advanced IMAP Tools

#### create_mailbox

Create a new mailbox/folder in your email account.

**Parameters:**

- `name` (required): Name of the mailbox to create

**Example:**

```typescript
{
  "name": "Projects"
}
```

#### delete_mailbox

Delete a mailbox/folder from your email account.

**Parameters:**

- `name` (required): Name of the mailbox to delete

**Example:**

```typescript
{
  "name": "OldFolder"
}
```

#### move_message

Move an email from one mailbox to another.

**Parameters:**

- `sourceMailbox` (optional): Source mailbox (default: "INBOX")
- `targetMailbox` (required): Target mailbox name
- `uid` (required): Email UID to move

**Example:**

```typescript
{
  "sourceMailbox": "INBOX",
  "targetMailbox": "Archive",
  "uid": 123
}
```

#### copy_message

Copy an email from one mailbox to another.

**Parameters:**

- `sourceMailbox` (optional): Source mailbox (default: "INBOX")
- `targetMailbox` (required): Target mailbox name
- `uid` (required): Email UID to copy

**Example:**

```typescript
{
  "targetMailbox": "Important",
  "uid": 456
}
```

#### advanced_search

Search emails with multiple criteria including sender, recipient, subject, body, date range, size, and flags.

**Parameters:**

- `mailbox` (optional): Mailbox name (default: "INBOX")
- `criteria` (required): Search criteria object with fields:
  - `from`: Search by sender
  - `to`: Search by recipient
  - `subject`: Search by subject text
  - `body`: Search by body text
  - `since`: Date filter (ISO 8601)
  - `before`: Date filter (ISO 8601)
  - `unseen`: Only unread emails (boolean)
  - `flagged`: Only flagged emails (boolean)
  - `larger`: Minimum size in bytes
  - `smaller`: Maximum size in bytes
- `limit` (optional): Maximum results, 1-100 (default: 10)

**Example:**

```typescript
{
  "criteria": {
    "from": "boss@company.com",
    "since": "2025-01-01",
    "unseen": true
  },
  "limit": 20
}
```

#### save_draft

Save an email as a draft in the Drafts folder without sending it.

**Parameters:**

- `to` (required): Recipient email address
- `subject` (required): Email subject
- `text` (optional): Plain text body
- `html` (optional): HTML body
- `from` (optional): Sender address
- `cc` (optional): CC recipient
- `bcc` (optional): BCC recipient

**Example:**

```typescript
{
  "to": "colleague@company.com",
  "subject": "Draft: Project Update",
  "text": "This is a draft email..."
}
```

#### get_thread

Get all emails in a conversation thread based on a message ID. Returns emails sorted chronologically with reply relationships.

**Parameters:**

- `mailbox` (optional): Mailbox name (default: "INBOX")
- `messageId` (required): Message ID to find thread for

**Example:**

```typescript
{
  "messageId": "<abc123@mail.example.com>"
}
```

**Response includes:**

- `messageId`: Unique message identifier
- `inReplyTo`: Parent message ID
- `references`: All related message IDs
- Full email content sorted by date

#### download_attachment

Download a specific attachment from an email. Returns the attachment content as base64-encoded data.

**Parameters:**

- `mailbox` (optional): Mailbox name (default: "INBOX")
- `uid` (required): Email UID
- `attachmentIndex` (required): Attachment index (0-based)

**Example:**

```typescript
{
  "uid": 789,
  "attachmentIndex": 0
}
```

**Response:**

```json
{
  "success": true,
  "filename": "report.pdf",
  "contentType": "application/pdf",
  "size": 102400,
  "content": "JVBERi0xLjQKJeLjz9MKM...",
  "encoding": "base64"
}
```

## Development

```bash
# Build the project
npm run build

# Watch for changes
npm run watch

# Run in development mode
npm run dev
```

## Security Notes

- Never commit credentials to version control
- Use environment variables for sensitive data
- Consider using App Passwords instead of regular passwords
- Use TLS/SSL for secure connections (port 465 or STARTTLS on 587)

## Common Email Providers

| Provider | SMTP Host | SMTP Port | IMAP Host | IMAP Port |
|----------|-----------|-----------|-----------|-----------|
| Gmail | smtp.gmail.com | 587/465 | imap.gmail.com | 993 |
| Outlook | smtp-mail.outlook.com | 587 | outlook.office365.com | 993 |
| Yahoo | smtp.mail.yahoo.com | 587 | imap.mail.yahoo.com | 993 |
| iCloud | smtp.mail.me.com | 587 | imap.mail.me.com | 993 |
| SendGrid | smtp.sendgrid.net | 587 | N/A | N/A |

**Notes:**

- Port 587: Use with STARTTLS (set `SMTP_SECURE="false"`)
- Port 465: Use with SSL/TLS (set `SMTP_SECURE="true"`)
- Port 993: Standard IMAP over SSL/TLS

## License

MIT

TDQS

B3.4/5.0

Scored across 16 tools

Disambiguation3/5

Several tools have overlapping purposes: `search_emails` and `advanced_search` both search, with `advanced_search` being a superset; `test_smtp_config` and `verify_connection` both verify SMTP connectivity; `fetch_emails` and `search_emails` have unclear boundaries. The descriptions help but do not fully resolve the ambiguity.

Naming Consistency5/5

Tool names consistently follow a `verb_noun` pattern with underscores (e.g., `send_email`, `list_mailboxes`, `move_message`). Even multi-word actions like `test_smtp_config` and `get_smtp_info` maintain the pattern. Naming is uniform and predictable.

Tool Count4/5

With 16 tools, the server is slightly above the ideal 3-15 range but still feels scoped to email functionality. Each tool addresses a distinct operation, though some could be consolidated (e.g., search tools, connection verification).

Completeness4/5

The server covers sending, retrieving, searching, mailbox management, attachments, and drafts. Notable gaps include no direct email deletion operation (though moving to trash is possible) and no explicit update draft operation. These are minor and mostly workaroundable.

Maintenance

ActivityInactive
ResponsivenessNo issues