MX Record Lookup
Enter a domain to see its mail servers with priorities, each one resolved to IP addresses, plus the detected mail provider. We also catch records pointing at a CNAME or at nothing at all.
What an MX record is
An MX record answers the question "where should mail for this domain be delivered". When a sending server sees the address john@example.com, it queries the MX records for example.com and gets back a list of mail server names with priorities. It then resolves those names to IP addresses and connects to the first one that responds.
Without MX records a domain accepts no mail. This is the first thing validation services check: if a domain has no MX, every address on it is undeliverable and there is no point looking further.
What the lookup shows
Besides the server list with priorities you get the IP addresses each name resolves to and the provider detected from those names — Google Workspace, Microsoft 365, Zoho and so on. It is a quick way to learn whose mail platform a company runs on before you contact them.
Two failure modes that a DNS panel will not reveal are checked separately: an MX pointing at a CNAME (forbidden by RFC 2181) and an MX whose hostname resolves to no address at all. In both cases the record looks fine in the panel while some mail never arrives.
Records used by popular providers
Google Workspace:
1 aspmx.l.google.com
5 alt1.aspmx.l.google.com
5 alt2.aspmx.l.google.comMicrosoft 365:
0 example-com.mail.protection.outlook.comA domain that accepts no mail:
0 .MX questions
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An MX record is the first filter in list validation, and far from the only one. uChecker verifies that the mailbox itself exists and flags spam traps and disposable addresses. The first 100 addresses are free.
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