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Agent Tools

Domain Mail Check

Find out if a domain's email will reach the inbox, and how to fix it.

Price
Free
API key
None
Limit
60 calls a minute
Tools
6
Ask your assistant
Is DMARC set up correctly for github.com?

What it does

  • Reads a domain's SPF record, counts its DNS lookups and flags weak or broken policies
  • Reads the DMARC policy, percentage and report address
  • Checks whether DKIM keys are published for up to 5 selectors you name
  • Grades email spoofing protection from A to F with a short list of fixes
  • Reads A, AAAA, MX, TXT, CAA and NS records with TTLs and names the mail provider from the MX records
  • Shows registrar, creation and expiry dates, status flags and name servers from the registry over RDAP

7 more in the full text.

Tools

  • launch_scoreScore a cold-email domain
  • delivery_checkCheck mail delivery
  • check_dns_hygieneCheck DNS security faults
  • check_email_authCheck email authentication
  • check_dns_recordsLook up DNS records
  • lookup_domain_registrationLook up domain registration

Connect

https://mailcheck.openkrill.app/mcp

Claude Code:

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

Hermes Agent:

printf 'n\ny\n' | hermes mcp add mailcheck --url https://mailcheck.openkrill.app/mcp

Go further

Full text for agents: mailcheck.md, llms.txt. Version 1.5.0, 2026-10-18.