Email domain check: MX, SPF, DKIM and DMARC
Open the mail checker and send a real message
What each record doesThe pieces that make a domain's mail trustworthy⌄
- MX
- MX names the servers that accept mail for the domain and the order to try them — a lower priority number is tried first. Without MX the domain cannot receive mail at all.
- SPF
- SPF lists the servers allowed to send mail as the domain. The catch is the 10 DNS lookup limit: every include, a, mx and exists spends one, and going over makes SPF fail entirely and silently.
- DKIM
- DKIM is a cryptographic signature on the message. DNS holds only the public key, at selector._domainkey.domain. Selector names are listed nowhere, so they have to be guessed or obtained from your mail provider.
- DMARC
- DMARC ties SPF and DKIM to the domain in the From header and tells receivers what to do with mail that fails: nothing (none), spam folder (quarantine) or reject. It also sends back reports on spoofing attempts.