email-check

Email posture for any domain: can it receive mail, can it be spoofed?

CommunityOnlineNo sign-inGlobalFreeCan modify data

What it can do

    What data it sees

    Do you need an account

    No: the server works without sign-in

    Email posture for any domain: can it receive mail, can it be spoofed? MX, SPF and DMARC.

    How to connect

    How to connect email-check to Claude

    The server address to paste into Claude settings:

    https://api.kaiv.ai/api/bridge/mcp/email-check-b6ab5250

    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 email-check to ChatGPT

    The server address to paste into ChatGPT settings:

    https://api.kaiv.ai/api/bridge/mcp/email-check-b6ab5250

    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 email-check to Cursor

    The server address to paste into Cursor settings:

    https://api.kaiv.ai/api/bridge/mcp/email-check-b6ab5250

    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 (4)

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

    check_email_domainFull email posture for a domain: can it receive mail, and can it be spoofed? Runs MX, SPF and DMARC lookups together and returns a plain-language verdict alongside the raw records: can_receive_mail, spoofable, and a list of specific findings. Use this as the default check before emailing an unfamiliar domain, when judging whether inbound mail claiming to be from a domain could be forged, or when auditing your own domains. Prefer this over the single-record tools unless you already know which record you need.
    get_dmarc_recordDMARC record, policy, and whether it actually protects. Returns the DMARC TXT record at _dmarc.<domain>, its policy (none / quarantine / reject), the percentage it applies to, and whether that policy protects against spoofing. Also flags the case of MULTIPLE DMARC records, which RFC 7489 requires receivers to treat as no policy at all — a domain in that state is unprotected however strict its records look. A policy of "none" is monitoring only and does not stop forged mail. Use when assessing whether mail claiming to be from a domain can be trusted.
    get_mx_recordsMail exchanger records for a domain. Returns the MX hosts in priority order and whether any exist. A domain with no MX records cannot receive mail, so sending to it will bounce. Use when you only need deliverability and not spoofing posture; use check_email_domain for the full picture.
    get_spf_recordSPF record and how strict it is. Returns the SPF TXT record, the qualifier on its `all` mechanism (fail / softfail / neutral / pass) and what that means in practice, plus whether more than one SPF record exists — which receivers treat as an error, leaving the domain unprotected. Use when diagnosing why mail from a domain is being rejected or marked.