MX record lookup
Where a domain's mail goes, and who may send it.
Enter a domain or an email address to see its MX records in priority order, the mailbox provider behind them, and whether its SPF and DMARC records would pass a Gmail or Yahoo bulk-sender check.
01How it works
Three DNS lookups, read for you.
MX records
The mail servers for the domain, lowest priority number first. A sender tries them in that order. A null MX (RFC 7505) means the domain accepts no mail at all.
SPF
The TXT record listing who may send as the domain. The ending decides the rest: -all rejects, ~all marks as suspicious, and more than 10 lookups breaks the record.
DMARC
The policy at _dmarc for mail that fails SPF and DKIM: none only monitors, quarantine sends it to spam, reject refuses it. Gmail and Yahoo require one from bulk senders.
FAQ
About MX records
What is an MX record?
An MX (mail exchanger) record is the DNS record that names the servers accepting email for a domain. Each has a priority number, and senders try the lowest number first. A domain with no MX record and no address record cannot receive mail.
What does it mean if a domain has no MX record?
Senders fall back to the domain's A or AAAA record, as RFC 5321 allows, so mail may still arrive. In practice most such domains are not set up for mail, and email verifiers treat addresses on them as high risk.
Why check SPF and DMARC together with MX?
MX shows whether a domain can receive mail. SPF and DMARC show whether mail claiming to come from it can be trusted. Since February 2024 Gmail and Yahoo require both from anyone sending more than 5,000 messages a day to their users.
Is ~all or -all better in SPF?
-all tells receivers to reject mail from servers not listed; ~all tells them to accept it but treat it as suspicious. With DMARC in place, ~all is the common, safer choice, because DMARC then decides the outcome and a forwarding hop does not cause outright rejection.
Does this tool check DKIM?
No. A DKIM key lives under a selector name that only the sender knows, such as google._domainkey, so it cannot be found from the domain alone. The DMARC result tells you whether failing mail is rejected either way.
Is there a limit?
No daily limit and no sign-up. A light automated-abuse guard runs in the background; ordinary use never meets it.
Checking MX is step one of verifying an address.
BounceIntel runs this lookup, then the mailbox check, then returns a verdict with reason codes. Start with 100 free credits.