MX lookup
Enter a domain to see its mail servers, priorities, IP addresses and the email provider behind them, plus any problems we can spot.
What an MX lookup tells you
MX records decide where email for a domain is delivered. A lookup shows each mail server and its priority, so you can confirm that new mailboxes are connected to Google Workspace, Microsoft 365 or another provider.
Using it for cold email
Check your own sending domains before you warm them up, and check a prospect's domain to see which provider receives their mail. If the MX records are missing or point to a CNAME, replies and bounces can fail.
Next steps
Pair this with the SPF checker, DKIM record checker and DMARC checker, or run the Domain Scanner for everything in one report.
MX lookup FAQ
What is an MX record?
An MX (mail exchanger) record tells the internet which servers receive email for a domain. Each record has a priority number, and servers with a lower number are tried first.
What does this MX lookup show?
It lists every MX host with its priority, resolves each host to its IP addresses, detects the email provider behind it, and flags common problems such as no MX records, a single mail server or an MX that points to a CNAME.
Why must an MX record not point to a CNAME?
Mail standards require MX targets to be real host names with A or AAAA records. A CNAME in between can make delivery unreliable, and some servers reject it.
What does a domain with no MX record do?
Sending servers fall back to the domain's A record, which often means mail is not set up properly. If you want a domain that never receives email, publish a null MX (priority 0 and a single dot).
Why do I need to check MX before cold email?
Your sending mailboxes and your prospects' domains both rely on correct MX records. Checking confirms that new domains are ready to receive replies and shows which provider a prospect uses.