Email security is the set of technical and administrative controls that reduce abuse of email-based entry points. It includes filtering spam and malware, blocking spoofed messages, authenticating sending domains with SPF, DKIM, and DMARC, encrypting sensitive mail, and protecting mailboxes with strong authentication and monitoring. The goal is to make it harder for attackers to deliver phishing, steal credentials, or use compromised accounts to move deeper into a network.
This matters because email remains one of the most common ways attackers start an intrusion. A single malicious link, attachment, or fake login page can lead to account takeover, ransomware deployment, or data theft. In defense, email security is part of recovery as well as prevention: after an incident, organizations should fix mail routing, tighten domain authentication, review mailbox rules, and remove exposed accounts. If those controls stay weak, the same email channel can keep serving as a repeat entry point.