MCP Server

Connect Claude, ChatGPT, Cursor, OpenCode and other AI agents to Inbound, and give agents their own mailboxes

Inbound’s MCP (Model Context Protocol) server lets AI assistants manage your domains, endpoints, addresses, emails and Guard rules. It can also create mailboxes: virtual email accounts that an agent can read, reply from and send from.

Server URL: https://inbound.new/mcp

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Connect

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With OAuth (recommended)

Add the URL to your client. When it connects, it opens Inbound in your browser; sign in and approve access. No API key needed.

Claude Code

claude mcp add --transport http inbound https://inbound.new/mcp

In Claude.ai and ChatGPT, add a custom connector with the same URL.

OAuth grants full access to your account, the same as an API key. The approval screen names the app and where it will send you back to; only approve apps you started the connection from.

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With an API key

For scripts and clients without OAuth, send an API key from settings as a bearer token:

{
  "mcpServers": {
    "inbound": {
      "type": "http",
      "url": "https://inbound.new/mcp",
      "headers": { "Authorization": "Bearer YOUR_API_KEY" }
    }
  }
}

The x-inbound-api-key header also works. Clients that only support STDIO can bridge with npx mcp-remote https://inbound.new/mcp --header "Authorization:Bearer ${INBOUND_API_KEY}".

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Give an agent its own mailbox

1. Ask your assistant to create a mailbox, e.g. “Create a mailbox for [e-mail] called Support Agent”. This calls create_mailbox, which returns a password shown once.
2. Connect the agent to https://inbound.new/mcp with Authorization: Bearer <mailbox password>.
3. The agent now has one email account: it can check its inbox, read, reply, send and archive. It can’t see other mail in your account or send as any other address. The Inbound API enforces this.

The same mailbox password works over IMAP and SMTP, and the mailbox appears in the dashboard. The address must be on a verified domain; new accounts can use their instant *.inbnd.dev domain.

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Mailbox tools

Tool	Description
whoami	The mailbox’s address, sending identity, scopes and unread count
list_messages	Inbox, archive or sent folder, with unread_only and search
read_message	Full message; marks it read
update_message	Mark read/unread, archive/unarchive
get_thread	The whole conversation
reply	Reply to a received message, threaded
send_email	Send a new email as the mailbox
download_attachment	Fetch an attachment

The mailbox password also gets the folder, folder-message, filter, spam and activity tools listed under Account tools, without a mailbox_id input, plus rotate_my_password. Filters, spam settings, activity and password rotation each need the matching selfService flag on the credential (filters, spam, activity, password); otherwise the API returns 403. See Access and limits.

Mailbox read/unread and archive actions update the same folders and flags used by IMAP and the HTTP mailbox API, not the dashboard’s separate account-level markers. Messages keep the inbox, archive and sent folder values; folderPath gives the exact folder when needed.

Immediate sends and replies from a Read & write mailbox save a copy to its Sent folder a few seconds after the send returns. Account-key sends and replies also save to enabled read/write mailboxes whose sending address (or login email, when no sending address is set) exactly matches the From address; a matching domain scope is not enough. Scheduled sends and older account sent records are not copied, and a failed copy never resends the email. See Sent copies.

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Account tools

Connected with OAuth or an API key, the server exposes 78 tools:

Area	Tools
Domains	list_domains, get_domain, create_domain, update_domain, delete_domain, enable_domain_dkim
Endpoints	list_endpoints, get_endpoint, create_endpoint, update_endpoint, delete_endpoint, test_endpoint
Addresses	list_email_addresses, get_email_address, create_email_address, update_email_address, delete_email_address
Emails	list_emails, get_email, send_email, reply_to_email, update_email, cancel_scheduled_email, pause_scheduled_email, resume_scheduled_email, retry_email_delivery, list_threads, get_thread, list_attachments, download_attachment
Mailboxes	list_mailboxes, create_mailbox, update_mailbox, delete_mailbox, rotate_mailbox_password, get_mailbox, list_mailbox_messages, read_mailbox_message, update_mailbox_message, get_mailbox_thread, send_from_mailbox, reply_from_mailbox, download_mailbox_attachment
Mailbox folders	list_mailbox_folders, create_mailbox_folder, rename_mailbox_folder, delete_mailbox_folder
Folder messages	list_folder_messages, get_folder_message, get_folder_message_raw, set_message_flags, move_message, copy_message, delete_folder_message, expunge_folder, append_message, list_folder_message_attachments, download_folder_message_attachment
Mailbox filters	list_mailbox_filters, get_mailbox_filter, create_mailbox_filter, update_mailbox_filter, delete_mailbox_filter, reorder_mailbox_filters, apply_mailbox_filters
Mailbox spam	get_mailbox_spam_settings, set_mailbox_spam_settings, add_spam_list_entry, remove_spam_list_entry
Mailbox activity	list_mailbox_activity, list_account_activity
Guard	list_guard_rules, get_guard_rule, create_guard_rule, update_guard_rule, delete_guard_rule, check_guard_rule, generate_guard_rule

update_mailbox and create_mailbox also take the access controls: protocols, allowed_ips, storage_quota_bytes, daily_send_limit and self_service. Folder tools work on the same folders, UIDs and flags as IMAP and the HTTP mailbox API; moving a message into Junk or back to INBOX marks it as junk or not junk for that mailbox only. Filters run on new mail; apply_mailbox_filters processes mail already in a folder. Activity tools return sign-ins, refused sign-ins, IMAP session events, quota errors and send failures for the last 30 days, never message content or passwords.

To expose fewer tools, add ?toolsets= with any of domains,endpoints,addresses,emails,mailboxes,guard, for example https://inbound.new/mcp?toolsets=mailboxes,emails.

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Example prompts

• “Show me unread email to [e-mail]”
• “Create a webhook endpoint for https://example.com/hooks and route [e-mail] to it”
• “Create a mailbox for [e-mail] and give me its MCP config”
• “Reply to the last email from [e-mail] saying we’ll ship Friday”
• “Block cold sales outreach with a Guard rule”
• “Add a filter to the support mailbox that moves invoices from [e-mail] into Finance”
• “Show failed sign-ins for [e-mail] this week”

The server is open source: inboundemail/mcp.