MCP Server – Send & manage emails, contacts and sending domains

Sidemail MCP server enables you to programmatically send and manage transactional emails, contacts, sending domains, and Messenger features – right from MCP agent mode in VS Code, Claude, Cursor, and other MCP clients.

What is MCP? Model Context Protocol (MCP) is a new open standard that makes it easier for AI systems to connect with external data and services. MCP acts a bit like an API for AI models – it provides a standard “language” for AI programs to access tools or data from the outside world. Learn more in our explanation article.

MCP server features

• Manage sending domains
• Test sending transactional emails
• Manage contacts and groups
• Create, update, and delete Messenger drafts
• Query sent emails and contacts

Prerequisites

• Node.js v18 or newer
• Sidemail API Key

Microsoft VS Code setup (assisted)

1. Open the Command Palette (Ctrl/Cmd + Shift + P).
2. Type “MCP: Add Server…” and select it.
3. Select "NPM Package".
4. Enter @sidemail/mcp and confirm it.
5. Confirm the installation.
6. Enter your Sidemail API key and confirm it.

Microsoft VS Code setup (manual)

Alternatively, you can install it manually by modifying the mcp.json configuration file.

1. Open the Command Palette (Ctrl/Cmd + Shift + P).
2. Type “MCP: Open User Configuration” and select it.
3. Add the configuration below and save changes.

{
	"servers": {
		"sidemail-mcp": {
			"type": "stdio",
			"command": "npx",
			"args": ["-y", "@sidemail/mcp"],
			"env": {
				"SIDEMAIL_API_KEY": "${input:sidemail-key}"
			}
		}
	},
	"inputs": [
		{
			"type": "promptString",
			"id": "sidemail-key",
			"description": "Sidemail API Key",
			"password": true
		}
	]
}

Claude Desktop setup

Edit (or create) the config file:

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

{
	"mcpServers": {
		"sidemail": {
			"command": "npx",
			"args": ["-y", "@sidemail/mcp"],
			"env": { "SIDEMAIL_API_KEY": "your-key" }
		}
	}
}

Cursor setup

Create or edit ~/.cursor/mcp.json:

CLI Usage

npx @sidemail/mcp

MCP Server Tools

Domains

• list-domains: List all sending domains
• create-domain: Add a new sending domain
• delete-domain: Remove a sending domain

Example – Adding a new sending domain:

Messenger

• list-messenger-drafts: List Messenger drafts
• get-messenger-draft: Get Messenger draft by ID
• create-messenger-draft: Create a Messenger draft
• update-messenger-draft: Update a Messenger draft
• delete-messenger-draft: Delete a Messenger draft

Example – Writing a product update email:

Groups

• list-groups: List all contact groups
• create-group: Create a new contact group
• update-group: Update a contact group

Contacts

• create-or-update-contact: Create or update a contact
• query-contacts: Query contacts with filters
• find-contact: Find a contact by email
• delete-contact: Delete a contact

Emails

• send-email: Send a transactional email (testing only)
• query-emails: Query sent emails

More resources

• Github repository: sidemail/sidemail-mcp-server
• NPM package: @sidemail/mcp
• Features overview