Mailtrap for Grok

Install Mailtrap in Grok

.mcp.json (in your project root)

{
  "mcpServers": {
    "mcp": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mcp-mailtrap"
      ],
      "env": {
        "MAILTRAP_API_TOKEN": "<MAILTRAP_API_TOKEN>",
        "MAILTRAP_ACCOUNT_ID": "<MAILTRAP_ACCOUNT_ID>"
      }
    }
  }
}

Grok Build reads Claude Code's .mcp.json and Claude Desktop's config unchanged, so a server you have already set up there needs nothing new. The Grok web app and X integration do not take custom servers. Grok docs