MultiMail enables AI agents to send, receive, and manage emails through the Model Context Protocol (MCP). Key capabilities include:
List mailboxes (
list_mailboxes): Discover all mailboxes available to your API key, including IDs, email addresses, oversight modes, and display names.Send email (
send_email): Send markdown emails (auto-converted to HTML) to one or more recipients with optional CC; supports gated oversight (pending_approvalstatus) and read-only mode detection.Check inbox (
check_inbox): List email summaries filterable by status (unread,read, orarchived).Read email (
read_email): Retrieve full email content (markdown body + attachment metadata) by ID; automatically marks it as read.Reply to email (
reply_email): Reply within an existing thread with automatic threading headers; supports oversight/read-only mode.Search identity (
search_identity): Look up the public identity document for any MultiMail address to verify an agent's operator, oversight mode, and capabilities.Update settings: Modify mailbox settings (display name, oversight mode, signature, webhooks) and account settings (org name, oversight email, physical address).
Delete mailbox: Permanently delete a mailbox (requires admin scope).
Account activation: Resend confirmation emails and activate accounts with confirmation codes.
Works with Claude.ai, Claude Desktop, Cursor, Windsurf, VS Code Copilot, ChatGPT Desktop, and other MCP clients.
Utilizes Markdown for email composition and provides incoming messages in clean Markdown format, enabling AI agents to handle email content without HTML parsing.
@multimail/mcp-server
MCP server for MultiMail. Give any AI agent email capabilities through the Model Context Protocol.
Quick start
npx @multimail/mcp-serverRequires MULTIMAIL_API_KEY environment variable. Get one at multimail.dev.
By using MultiMail you agree to the Terms of Service and Acceptable Use Policy.
Related MCP server: MCP Email Server
Setup
Option A: Remote server (recommended)
No install required. Connect directly to our hosted server. Authenticates via OAuth in the browser.
{
"mcpServers": {
"multimail": {
"type": "url",
"url": "https://mcp.multimail.dev/mcp"
}
}
}Works with Claude.ai, Claude Desktop, Claude Code, and any client that supports remote MCP servers.
Option B: Local server (stdio)
Run the server locally. API key is passed as an environment variable.
{
"mcpServers": {
"multimail": {
"command": "npx",
"args": ["-y", "@multimail/mcp-server"],
"env": {
"MULTIMAIL_API_KEY": "mm_live_...",
"MULTIMAIL_MAILBOX_ID": "01KJ1NHN8J..."
}
}
}
}Where to add this
Client | Config file |
Claude Code |
|
Claude Desktop |
|
Cursor |
|
Windsurf |
|
Copilot (VS Code) |
|
OpenCode |
|
ChatGPT Desktop | Settings > MCP Servers |
Any MCP client | Consult your client's docs for config location |
Environment variables
Variable | Required | Description |
| Yes | Your MultiMail API key ( |
| No | Default mailbox ID. If not set, pass |
| No | API base URL. Defaults to |
First-run setup
On first use, MultiMail will prompt you to configure your mailbox. You can also run this explicitly using the configure_mailbox tool:
Oversight mode: How much human approval is required (
gated_send,monitored,autonomous, etc.)Display name: Sender name shown in emails
CC/BCC defaults: Automatically copy addresses on all outbound emails
Scheduling: Enable/disable scheduled send and set default gate timing
Signature: Email signature block
If you skip this step, MultiMail will remind you on your first tool call.
Tools
Tool | Description |
| List all mailboxes available to this API key |
| Set up mailbox preferences: oversight mode, display name, CC/BCC, scheduling, signature |
| Send an email with a markdown body. Supports attachments, |
| List emails with filters: status, sender, subject, date range, direction, attachments, cursor pagination |
| Get full email content including markdown body, attachments, tags, and delivery timestamps |
| Reply to an email in its existing thread. Supports attachments and |
| Download an email attachment as base64 with content type |
| Get all emails in a conversation thread with participants and metadata |
| Cancel a pending or scheduled email |
| Schedule an email for future delivery with a required |
| Edit a scheduled email's delivery time, recipients, subject, or body before it sends |
| Update mailbox settings (display name, oversight mode, signature, webhooks) |
| Update account settings (org name, oversight email, physical address) |
| Permanently delete a mailbox (requires admin scope) |
| Resend the activation email with a new code |
| Activate an account using the code from the confirmation email |
| Set, get, or delete key-value tags on emails (persistent agent memory) |
| Add a contact to your address book with optional tags |
| Search address book by name or email |
| Get account status, plan, quota, sending enabled, enforcement tier |
| Create a new mailbox (requires admin scope) |
| Request an oversight mode upgrade (trust ladder) |
| Apply an upgrade code from the operator |
| Check quota and usage stats for the billing period |
| List emails awaiting oversight decision (requires oversight scope) |
| Approve or reject a pending email (requires oversight scope) |
| Delete a contact from the address book |
| List suppressed email addresses |
| Remove an address from the suppression list |
| List all API keys (requires admin scope) |
| Create a new API key with scopes (requires admin scope) |
| Revoke an API key (requires admin scope) |
| Get account audit log (requires admin scope) |
| Permanently delete account and all data (requires admin scope) |
| Block until a new email arrives matching filters, or timeout (max 120s) |
| Create a webhook subscription for real-time email event notifications |
| List all webhook subscriptions for this account |
| Delete a webhook subscription |
How it works
You write email bodies in markdown. MultiMail converts to formatted HTML for delivery.
Incoming email arrives as clean markdown. No HTML parsing or MIME decoding.
Threading is automatic. Reply to an email and headers are set correctly.
Sends return
pending_scanstatus while the email is scanned for threats. If your mailbox uses gated oversight, the status transitions topending_send_approvalfor human review. Do not retry or resend.Verify other agents by checking the
X-MultiMail-Identitysigned header on received emails.
Development
npm install
npm run dev # Run with tsx (no build needed)
npm run build # Compile TypeScript
npm start # Run compiled versionTesting
echo '{"jsonrpc":"2.0","method":"tools/list","id":1}' | MULTIMAIL_API_KEY=mm_live_... node dist/index.jsLicense
MIT