MX record checker
Type a domain or an email address. See its mail servers, who hosts its email, and whether it can receive email at all. Free, no signup.
What is an MX record?
An MX (mail exchanger) record tells the world which server receives email for a domain. When someone sends an email to [email protected], their mail server looks up the MX records of company.com and delivers the message there.
A domain can have several MX records. Each has a priority number: the lowest number is tried first, and the others are backups.
What the result means
- pass The domain has mail servers and they have addresses. It can receive email.
- warning Something is off but mail may still arrive: there is no MX record (mail goes to the website server instead), or some backup servers are broken.
- problem The domain can't receive email: it doesn't exist, it has a "null MX" record that says "no email here", or none of its mail servers work.
Why check MX records?
- Before you email someone new: a domain with no working mail server means a hard bounce, and bounces hurt your sender reputation.
- After moving email providers: when you switch to Google Workspace or Microsoft 365, the MX records must point to the new provider, or mail keeps going to the old one.
- To see who hosts a company's email: the provider column shows Google, Microsoft, Zoho, or a security gateway like Proofpoint or Mimecast in front of the real mailbox.
Common MX problems
"No MX record"
The domain has a website but nobody set up email. Senders then try the website server, which almost never accepts mail. If this is your domain, add the MX records your email provider gives you.
"Mail server has no address"
The MX record points to a host name that doesn't exist, often after a provider change or a typo in the DNS settings. Fix the host name or remove the old record.
"Null MX"
A single MX record with the host . means "this domain never receives email" (RFC 7505). That's on purpose, for domains used only for websites or only for sending.
Questions
Does a working MX record mean an email address exists?
No. It means the domain can receive email. Whether jane@ is a real mailbox at that domain is a separate question that only the mail server can answer.
How is the lookup done?
Your browser asks Cloudflare's public DNS (1.1.1.1) over HTTPS. Only the domain name is sent; nothing is stored by BounceLens.
Can I check a whole list of email domains?
Yes. The email list checker looks up the MX records of every domain in a list and marks the addresses that will bounce.
More free checks
- SPF, DMARC and DKIM checker: can your emails be trusted by Gmail and Outlook?
- Free email checker: check addresses for typos, dead domains and throwaway services.
- Disposable email checker: find throwaway addresses like Mailinator.