Cursor connects remote MCP servers by URL. Three transports are supported: stdio (local process), SSE and Streamable HTTP; the remote ones — SSE and Streamable HTTP — authorize via OAuth. Email Massivo belongs to this group.

Authorization uses OAuth 2.1: you add the MCP server URL → Cursor contacts the server without a token and requests authorization → the Email Massivo sign-in page opens, you log in to your account and click "Allow" → Cursor receives an access token, and the connection is ready to use.

MCP server URL: https://mcp.emailmassivo.com/mcp

Cursor has no separate form with "name" and "URL" fields like Claude and ChatGPT: the add-server button opens the mcp.json file directly in an editor tab inside Cursor, and the server is added there manually.

The add-server form can be opened in two ways — depending on which interface you use.

IDE

  1. Click the gear in the top-right corner of the window → Cursor Settings opens → select "Customize" in the left menu.


Cursor Settings in the IDE: gear (1) → "Customize" in the left menu (2)

  1. Switch to the MCPs tab and click the "New MCP Server" / "Add a Custom MCP Server" card.


IDE: Customize tab → MCPs (1) → "New MCP Server" / "Add a Custom MCP Server" card (2)

Agents Window

  1. The "Customize" item is right in the left sidebar — there is no need to open separate settings. Switch to the MCPs tab and click the "New MCP Server" card.


Agents Window: "Customize" in the sidebar (1) → MCPs tab (2) → "New MCP Server" (3)

For both methods

  1. Cursor opens mcp.json with the template { "mcpServers": {} } — in the IDE this is a new tab inside the same window; in the Agents Window the file opens in a separate small window.

  2. Inside mcpServers, enter the server block:

{
  "mcpServers": {
    "email_massivo": {
      "url": "https://mcp.emailmassivo.com/mcp"
    }
  }
}

  1. If the file already contains other servers, add email_massivo as another key inside mcpServers without creating a second such block. The type field does not need to be specified for remote servers — it is required only for local stdio servers.

  2. Save the file with Ctrl+S (Cmd+S on macOS).

  3. Return to the Customize → MCPs tab. Right after saving, the server usually lands not in "Connected" but in "Needs Attention" — this is normal, authorization has not been completed yet.


MCPs tab → "Needs Attention" block: email_massivo with the status "Needs authentication" and the "Authenticate" button

  1. Click email_massivo in the list — the "Configure email_massivo" window opens. Next to the "Local" row there is an "Authenticate" button: click it.


"Configure email_massivo" window: (1) if there is no "Authenticate" button — click "Reload" first, (2) after reloading, "Authenticate" appears — click it

  1. If there is no "Authenticate" button and something else is shown instead (for example, "Needs Authentication" without a button) — click "Reload" in the bottom-left corner of the window: after reloading, the "Authenticate" button appears.

  2. After clicking "Authenticate", the browser opens with the Email Massivo authorization page. Log in to your account and click "Allow".


Email Massivo authorization page — "Allow" button

  1. Check the result: the server should move from "Needs Attention" to "Connected", and its tools should appear in the chat in the Available Tools list.

By default, Cursor asks for confirmation before each MCP tool call; the call arguments can be expanded with the arrow next to the tool name. You can temporarily disable the server without removing it using the toggle in Customize.

If the server does not connect, open the Output panel (Cmd/Ctrl + Shift + U) and select "MCP Logs" in the dropdown — it shows initialization, authorization and server crash errors.