scan.mx Email Diagnostics

Check whether the domain and its mail server IPs are listed on the Spamhaus (ZEN, DBL, ZRD, AuthBL), SpamCop, GBUdb and PSBL blocklists.

Check DKIM signing keys for a domain. Without a selector, common provider selectors are probed. Pass an explicit selector to look up that exact key at selector._domainkey.

Check the domain DMARC policy at _dmarc: presence, policy strength (none/quarantine/reject), and reporting.

Run the full email and DNS deliverability check for a domain: MX, SPF, DKIM, DMARC, DNS health, provider detection, and blacklists. Returns a letter grade (A to F), a 0 to 100 score, and every individual check with its RFC reference. Set include_smtp to also run a live SMTP probe of the mail servers: the probe is non-blocking, so when smtp_status is "pending" or "running" call this tool again (poll_after_seconds hints how long to wait) until smtp_status is "complete" and the SMTP checks appear i…

Check the MX records of a domain: presence, hostnames, resolution, null-MX, and common misconfigurations.