DNS
What is MX Record (Mail Exchange Record)?
A DNS record that specifies which mail servers receive email for a domain, in priority order.
An MX record maps a domain to the hostnames of the servers responsible for accepting its inbound mail, each weighted with a preference number where lower values are tried first. Sending servers query the recipient domain's MX records to know where to deliver a message. MX records point to hostnames, never directly to IP addresses, and those hostnames must resolve via A records.
Why it matters for cold email
A domain used for cold email needs valid MX records so it can receive replies, bounces, and verification messages; a domain with no MX looks abandoned and untrustworthy. Mailbox providers and email verifiers also check MX records to confirm an address belongs to a real, mail-accepting domain.
Related terms
Stop guessing at deliverability.
Scheduler Zero handles authentication, warmup, and sender reputation so your cold email lands in the inbox, not the spam folder.