Domain Mail Check

npx add-mcp 'https://mailcheck.openkrill.app/mcp'

check DMARC policy for a domain

check_email_auth reads the domain's DMARC policy, its percentage and its report address, and grades protection against spoofing from A to F.

The answer lists the problems found and a short list of fixes. It also follows the SPF include and redirect terms and counts the DNS lookups against the limit of 10. It checks the exact domain you give, so a parent domain's record is not inherited. Tool: check_email_auth on https://mailcheck.openkrill.app/mcp.

is my domain ready for cold email

launch_score gives a domain a score from 0 to 100 and a verdict, from its SPF, DKIM, DMARC, MX, domain age and name pattern.

Each rule says whether it is a published requirement or only common advice, and links its source. It reads public DNS and the registry only, so it cannot see sender reputation or warm-up. Tool: launch_score on https://mailcheck.openkrill.app/mcp.

will Gmail and Outlook accept my email

delivery_check gives one verdict for Gmail and Outlook, the top 3 causes and one fix for each, from the published sender rules and 6 free blocklists.

Pass the domain and the IP your mail leaves from. It sends no test message, so it cannot promise the inbox. It also checks DKIM keys, on 10 usual selector names or on the selectors you name. Tool: delivery_check on https://mailcheck.openkrill.app/mcp.

which email provider does a domain use

check_dns_records names the mail provider from the domain's MX hosts.

It also reads A, AAAA, TXT, CAA and NS records with their TTLs, and the CAA records show which certificate authorities may issue for the domain. Tool: check_dns_records on https://mailcheck.openkrill.app/mcp.

when does a domain expire and who is the registrar

lookup_domain_registration returns the registrar, the creation, update and expiry dates and the days left until expiry.

The data comes from the registry over RDAP. Registrant and contact details are never returned, so the answer cannot say who owns the domain. Tool: lookup_domain_registration on https://mailcheck.openkrill.app/mcp.

Run it yourself

This page does not return live data. Call the tool on the server to get it. The server is Domain Mail Check at https://mailcheck.openkrill.app/mcp, with no key. Install steps: ChatGPT, Claude, Cursor, VS Code, Pi. A call to check_email_auth was posted to the live server on 2026-10-11, and the install pages show it. The full tool list is in the install guides.