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mcp/harbor
Grok

MailboxValidator for Grok

io.github.mailboxvalidator/mcp-mailboxvalidator

Email validation MCP server using the MailboxValidator API. It can validate email addresses.

client:Grok transport:stdio runtime:npm

Install MailboxValidator in Grok

.mcp.json (in your project root)

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{
  "mcpServers": {
    "mcp-mailboxvalidator": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mcp-mailboxvalidator"
      ],
      "env": {
        "MAILBOXVALIDATOR_API_KEY": "<MAILBOXVALIDATOR_API_KEY>"
      }
    }
  }
}

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

MailboxValidator in other clients

MailboxValidator MCP server