Connect MultiMail to Claude Desktop via MCP so Claude can send, read, and manage email with built-in human oversight at every step.
Claude Desktop is Anthropic's native application for interacting with Claude. By connecting MultiMail through the Model Context Protocol, you give Claude the ability to send emails, check inboxes, manage contacts, and handle email workflows directly from your conversation.
MultiMail's oversight modes let you control how much autonomy Claude has. Start with gated mode where every outbound email requires your approval, then graduate to monitored or autonomous as trust builds. The MCP integration works through stdio transport, making setup straightforward.
This guide walks you through configuring Claude Desktop to use MultiMail's MCP server, the available email tools, and practical examples for common workflows.
Sign up at multimail.dev and create an API key from your dashboard. You'll need this to authenticate the MCP server.
In the MultiMail dashboard, create a mailbox for Claude to use. Choose a subdomain like [email protected] and set the initial oversight mode to gated_send.
Locate and edit your Claude Desktop configuration file. On macOS it's at ~/Library/Application Support/Claude/claude_desktop_config.json. On Windows it's at %APPDATA%\Claude\claude_desktop_config.json. Create the file if it doesn't exist.
# macOS
open ~/Library/Application\ Support/Claude/claude_desktop_config.json
# Windows
notepad %APPDATA%\Claude\claude_desktop_config.jsonAdd the MultiMail MCP server configuration to your claude_desktop_config.json file. Replace the API key with your actual key.
{
"mcpServers": {
"multimail": {
"command": "npx",
"args": ["-y", "@multimail/mcp-server"],
"env": {
"MULTIMAIL_API_KEY": "mm_live_your_key_here"
}
}
}
}Quit and reopen Claude Desktop for the configuration to take effect. You should see a hammer icon indicating MCP tools are available. Click it to verify MultiMail tools are listed.
| Tool | Description | Example |
|---|---|---|
| send_email | Send an email from your agent mailbox to any recipient. | Send a follow-up email to a client after a meeting. |
| reply_email | Reply to a received email, maintaining the thread context. | Reply to a customer support inquiry with a resolution. |
| check_inbox | Check a mailbox for new or unread messages. | See if any new emails arrived in the past hour. |
| read_email | Read the full content of a specific email including headers and body. | Read the details of an incoming invoice email. |
| create_mailbox | Create a new agent mailbox on your MultiMail account. | Create a dedicated mailbox for handling support tickets. |
| list_mailboxes | List all mailboxes on your MultiMail account. | See all available mailboxes before choosing which one to send from. |
| get_thread | Retrieve an entire email thread to see the full conversation history. | Pull up the complete back-and-forth with a vendor. |
| search_contacts | Search your contact list by name, email, or tags. | Find all contacts at a specific company domain. |
| add_contact | Add a new contact to your MultiMail contact list. | Save a new business contact after receiving their first email. |
| tag_email | Tag or categorize an email for organization and filtering. | Tag an email as 'urgent' or 'invoice' for later retrieval. |
| list_pending | List all emails currently awaiting human approval. | Review the queue of drafted emails before approving them. |
| decide_email | Approve or reject a pending email in the oversight queue. | Approve a drafted response after reviewing its content. |
{
"mcpServers": {
"multimail": {
"command": "npx",
"args": ["-y", "@multimail/mcp-server"],
"env": {
"MULTIMAIL_API_KEY": "mm_live_your_key_here"
}
}
}
}The minimal configuration needed to connect MultiMail to Claude Desktop. Add this to your claude_desktop_config.json file.
Check my MultiMail inbox and give me a summary of any unread messages. For each email, include the sender, subject, and a one-line summary of the content.A natural language prompt you can use in Claude Desktop to have it check your email and provide a summary.
Send an email to [email protected] from my agent mailbox. Subject: Q1 Report Follow-up. Body: Thank them for the Q1 report, note that revenue figures look strong, and ask when we can schedule a review call next week.When the mailbox is in gated_send mode, Claude will draft the email and it will queue for your approval before sending.
{
"mcpServers": {
"multimail": {
"command": "npx",
"args": ["-y", "@multimail/mcp-server"],
"env": {
"MULTIMAIL_API_KEY": "mm_live_your_key_here"
}
},
"other-server": {
"command": "npx",
"args": ["-y", "@other/mcp-server"]
}
}
}If you use multiple MCP servers alongside MultiMail, add them all to the same config file.
Configure your mailbox with gated_send oversight mode initially. This means Claude drafts emails but they queue for your approval before sending. You can review and approve directly in the MultiMail dashboard or ask Claude to list pending emails.
After restarting Claude Desktop, click the hammer icon in the chat input area to see all available MCP tools. If MultiMail tools don't appear, check your config file for JSON syntax errors.
Instead of using one mailbox for everything, create separate mailboxes for support, outreach, and notifications. This keeps threads organized and lets you set different oversight levels per use case.
If tools aren't working as expected, Claude Desktop logs MCP server output. On macOS, check ~/Library/Logs/Claude/ for error messages from the MultiMail MCP server.
Email infrastructure built for AI agents. Verifiable identity, graduated oversight, and a 38-tool MCP server. Formally verified in Lean 4.