Microsoft Exchange is an email and calendar platform used to store mailboxes, manage contacts, and coordinate scheduling. It is often deployed on-premises, in hybrid setups, or exposed through webmail interfaces such as Outlook on the web (OWA).
Exchange matters in cyber security because it sits at the center of business communication and identity relationships. If attackers compromise Exchange, they may read messages, steal credentials, abuse delegated mailbox access, create hidden mail rules, or use the server as a foothold for broader espionage. Because many organizations publish webmail for remote access, Exchange becomes a high-value internet-facing target. Defenders should treat it as a sensitive perimeter service, keep it patched, restrict unnecessary exposure, monitor OWA and EWS activity, and watch for unusual sign-ins, forwarding rules, or mailbox permission changes.