MX recordlookup.
Look up the mail servers for any domain, in the order they're tried, and see which provider handles its email.
How it works
- Enter a domainAny company or your own
- See its mail serversIn priority order, with addresses
- Know the providerGoogle, Microsoft or another host
Free, no sign-up. Checked live from our server. Nothing is stored.
The tool
Look up MX records
Who handles a domain's email, and the servers mail goes to, in order.
Reading MX records.
What the result means, and how to fix what it finds.
What MX records are
MX (mail exchange) records tell the internet which servers accept email for a domain. Every email sent to that domain goes to one of them. Without any, the domain can't receive email at all: messages to it bounce.
Priority
Each MX record has a number. Senders try the lowest number first and fall back to higher ones if it doesn't answer. Records with the same number share the load. Google Workspace domains usually list aspmx.l.google.com first; Microsoft 365 domains use one record ending in mail.protection.outlook.com.
Why the provider matters for cold email
Knowing a prospect's email provider helps you send well. Google and Microsoft filter differently, and many senders match the provider: Google mailboxes for Google recipients. The provider also tells you how reliable verification will be: Google and Microsoft reject unknown addresses, while some self-hosted servers accept every address.
Checking your own domain
Your sending domain needs MX records too, because people reply to cold email. If you use Google Workspace or Microsoft 365, add the MX records they give you. A domain that sends but can't receive looks suspicious to filters, and you lose the replies.
Common MX setups
Google Workspace uses one record, smtp.google.com, for newer domains, or five aspmx records with priorities from 1 to 10 for older setups; both are correct. Microsoft 365 uses a single record named after your domain, ending in mail.protection.outlook.com. Zoho, Fastmail and others have their own names. An email security gateway, a service that filters spam before it reaches the mailbox, often sits in front, so the MX shows the gateway rather than the mailbox provider. If you see records for two different providers on one domain, mail may be split between them, usually by mistake after a move. When you move a domain to a new provider, remove the old MX records once the new ones work, or some email keeps arriving at the old one.
In mailzy
Google Workspace mailboxes, ready in 48 hours.
mailzy sets up MX, SPF, DKIM and DMARC on your domain, creates the mailboxes and warms them up.
Questions before you start.
Ask us on the chat if yours isn't here. A real person answers.
What if a domain has no MX record?
It can't receive email. Any address at that domain will bounce, so remove it from your list.
Does the MX record affect sending?
Not directly, but a sending domain that can't receive replies looks suspicious, and you miss every reply.
Can MX records show the email provider?
Usually yes. The mail server names show whether it's Google, Microsoft, Zoho or a self-hosted server.
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Open the toolEverything for cold email, in one place.
Start free for 14 days. No card needed.