Look up a domain's MX records (the mail servers that receive its email) and find out instantly whether the domain can accept mail at all. Enter a domain or an email address; the check runs against live DNS. No account, no card.
Enter a domain or an email address. We resolve its MX records - the mail servers responsible for receiving its email.
What an MX record lookup tells you
MX (Mail Exchange) records are the DNS entries that route email. A lookup answers two practical questions:
Can this domain receive email?
A domain with no MX record can't accept mail - every address at it will hard-bounce. This is the single fastest way to rule out a dead or mail-less domain.
Which servers handle its mail?
The records name the receiving mail servers and their priority order - often revealing the mail provider behind a custom domain (Google Workspace, Microsoft 365, and so on).
Where an MX check fits in verification
The MX lookup is the second stage of the verification pipeline - a cheap, instant DNS check that eliminates dead domains before any slower work runs. It can rule an address out (no mail route), but it can't confirm a mailbox exists. That takes an SMTP conversation with the server, which the full check adds. If you build your own validation, the Node.js and Python guides show how to run the MX layer in code.
MX record lookup FAQ
An MX (Mail Exchange) record is a DNS entry that names the mail servers responsible for receiving email for a domain, each with a priority number. When someone sends mail to name@example.com, their server looks up example.com's MX records to find where to deliver it. A domain with no MX record can't receive email.
Lower numbers are preferred. A sending server tries the lowest-priority MX host first and falls back to higher-numbered ones if it's unavailable. Equal priorities are used interchangeably for load balancing. The numbers are relative - only their order matters, not the specific values.
No. An MX record only confirms the domain can receive mail somewhere - it says nothing about whether a specific mailbox exists. An address at a domain with valid MX records can still hard-bounce if that particular inbox was never created or has been closed. Confirming the mailbox needs a full SMTP check.
Either the domain doesn't exist, or it exists but was never configured to receive email (common for parked domains, or domains used only for a website). Some domains accept mail on an A record as an implicit fallback, but a missing MX usually means mail to that domain will bounce.
Yes - free, no signup, with a small hourly limit. For confirming actual mailboxes across a whole list, the full verification pipeline runs the MX check plus the SMTP mailbox probe on every address; you can start free with 100 credits.
Confirm mailboxes, not just domains
Full verification adds the SMTP mailbox probe and catch-all detection on every address - start free with 100 credits, no card required.
