Terminology Index
Glossary
2953 terms
M32
MX Record
A DNS record that specifies the mail servers responsible for receiving email for a domain. Defenders use it to understand email routing, recognize legitimate mail infrastructure, and spot signs of email-related attacks.
An MX (mail exchanger) record in DNS tells the rest of the internet which servers handle incoming email for a domain. Understanding MX records helps defenders interpret email infrastructure: verifying legitimate mail servers, checking how external mail flows in, recognizing when an attacker stands up lookalike mail infrastructure or hijacks records. It is part of the DNS toolkit underlying email security alongside SPF, DKIM, and DMARC.
Introduced in: Networking Foundations
Examples
- Looking up a domain's MX records to find its mail servers.
- Verifying that mail comes from the expected MX-listed server.
- Spotting suspicious DNS changes to MX records as potential attack signs.
