XTND | MCP | ONE

Model Context Protocol (MCP) server for one.com mailboxes.

CommunityOnlineAPI key requiredGlobalFreeRead-only

What it can do

  • List Folders: List all mailboxes/folders in the one.com mail account with message and unread counts.
  • Create Folder: Create a new folder or mailbox in the one.com mail account.
  • Rename Folder: Rename an existing mailbox/folder.

What data it sees

Do you need an account

An API key from the service settings is required

Model Context Protocol (MCP) server for one.com mailboxes. Full email management (IMAP/SMTP) for Claude and AI agents.

How to connect

How to connect XTND | MCP | ONE to Claude

The server address to paste into Claude settings:

https://mcp-one--xtnd.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect XTND | MCP | ONE to ChatGPT

The server address to paste into ChatGPT settings:

https://mcp-one--xtnd.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect XTND | MCP | ONE to Cursor

The server address to paste into Cursor settings:

https://mcp-one--xtnd.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (15)

Raw names from tools/list. Only developers need these.

list_foldersList all mailboxes/folders in the one.com mail account with message and unread counts.
create_folderCreate a new folder or mailbox in the one.com mail account.
rename_folderRename an existing mailbox/folder.
delete_folderDelete a folder/mailbox from the one.com mail account.
search_emailsSearch for emails in one.com mailbox using filters (query, folder, sender, recipient, flags).
get_recent_emailsRetrieve the most recent emails from a mailbox folder with envelopes.
get_email_contentFetch full email content by UID from a folder. Body is converted to clean Markdown.
get_email_threadRetrieve the full conversation thread for a given email UID or Message-ID.
mark_emailsMark emails as read, unread, flagged, or unflagged.
move_emailsMove emails from a source folder to a destination folder.
delete_emailsDelete emails by moving them to Trash (soft delete) or permanent expunge.
send_emailSend a new outbound email via one.com SMTP server (send.one.com:465).
reply_emailReply to an existing email with automated In-Reply-To and References headers.
forward_emailForward an existing email to new recipients with original header context.
create_draftCreate an email draft in the one.com Drafts folder without sending.