MCP server

Domain Mail Check

app.openkrill/mailcheck

Checked 25 Oct 2026, 20:29 UTC · Connected to it and listed its tools

Check a domain's email DNS, whether Gmail and Outlook accept its mail, and its registration.

Website Source

At a glance

Type

MCP server

Publisher

openkrill.app (verified by the MCP Registry)

Status

Working at last check

Tools

7

Token cost

About 2,576 tokens per request

Sets up in

Claude Code, Claude Desktop, Codex, Gemini CLI, Cursor, VS Code, Antigravity, ChatGPT, OpenAI API, Grok

Last checked

25 Oct 2026, 20:29 UTC

Connect it to your agent

Add to CursorAdd to VS CodeVS Code Insiders

Opens the app, which shows the server and asks you to confirm. For other apps, copy the setup below.

Claude Code

claude mcp add --transport http mailcheck https://mailcheck.openkrill.app/mcp

Claude Desktop

Settings → Connectors → Add custom connector, and paste the URL.

Codex (config.toml)

[mcp_servers.mailcheck]
url = "https://mailcheck.openkrill.app/mcp"

Gemini CLI

{"mcpServers":{"mailcheck":{"httpUrl":"https://mailcheck.openkrill.app/mcp"}}}

Cursor

{"mcpServers":{"mailcheck":{"url":"https://mailcheck.openkrill.app/mcp"}}}

VS Code

{"servers":{"mailcheck":{"type":"http","url":"https://mailcheck.openkrill.app/mcp"}}}

Antigravity

agy mcp add mailcheck https://mailcheck.openkrill.app/mcp

ChatGPT

Settings → Apps & Connectors → Advanced settings: turn on Developer mode, then Create a connector and paste the URL. Which plans can do this varies.

OpenAI API (Responses tools)

{"type":"mcp","server_label":"mailcheck","server_url":"https://mailcheck.openkrill.app/mcp","require_approval":"always"}

Grok (xAI API tools)

{"type":"mcp","server_label":"mailcheck","server_url":"https://mailcheck.openkrill.app/mcp"}

Tools

• check_dns_records ~294 tokens
  Use this when the user asks for a domain's DNS records, its mail provider or which certificate authorities may issue for it, such as "which mail provider does acme.io use?" or "show the MX and CAA records for github.com". Pass the domain and optionally up to 6 record types from A, AAAA, MX, TXT, CAA
• check_email_auth ~372 tokens
  Use this when the user asks whether a domain's email is set up correctly, such as "is DMARC set up for github.com?" or "check SPF and DKIM for example.com". Pass the domain and, if known, up to 5 DKIM selector names. Returns SPF (policy, DNS lookup count, issues), DMARC (policy, percentage, report a
• delivery_check ~701 tokens
  Use this when the user asks whether mail from a domain will reach Gmail or Outlook, or why it is rejected or goes to spam, such as "will Gmail accept mail from example.com sent from 203.0.113.7?". Pass the domain, the sending IPv4 address if known, the return-path domain (mail_from) if known and, op
• launch_score ~419 tokens
  Use this when the user asks whether a new or secondary domain is ready for cold email or outreach, or wants a score for a sending domain, such as "is acme-mail.com ready for cold email?". Pass the domain and, optionally, up to 5 DKIM selectors. Returns a score from 0 to 100, a verdict (ready, almost
• lookup_domain_registration ~213 tokens
  Use this when the user asks who a domain is registered with or when it expires, such as "when does openai.com expire and who is the registrar?". Pass the domain. Returns whether it is registered, the registrar, creation, update and expiry dates, days until expiry, registry status flags, name servers

Browse

• GitHub tools
• IPv4 tools
• Domains and DNS
• Email
• GitHub and code hosting
• Calling other AI models

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