An email security gateway acts as a gatekeeper, scanning inbound and outbound emails to detect and block harmful content before it reaches user inboxes or leaves the organization. The best solutions offer features like advanced threat protection to block malware and phishing attempts (look for solutions that are always on top of the latest malware and phishing techniques), outbound email filtering to mitigate/prevent possible data leaks, robust encryption options to secure sensitive data, spam filtering to reduce unwanted emails, and easy integration with existing systems. It’s helpful to have analytics and reporting tools to monitor email threats and support compliance requirements around data protection.