Simple definition
An email security gateway inspects inbound or outbound messages according to protection and mail-flow policies.
Purpose and use
It helps reduce spam, phishing, dangerous attachments and some unauthorized data transfers.
How does it work?
Depending on deployment, it evaluates senders, authentication results, links and files, then permits, blocks or quarantines a message.
Key points
- Example: a suspicious attachment is held for analysis before a decision on release.
- Verify the actual mail path, logs, quarantine rules and procedures for handling false positives.
Points to watch
A gateway does not guarantee that a business request from a compromised account is legitimate. Mailbox access and payment verification still need protection.
In short
An email gateway protects mail flow under a policy and complements identity and business-process controls.