Not every risky email should be blocked outright. Some messages may be legitimate but still deserve extra scrutiny. Until now, email security has largely followed a simple model: a message is either delivered or blocked. While this works well for clearly malicious emails, many modern attacks operate in a gray area where the risk is real, but not high enough to justify rejecting the message.

Cybercriminals have been relying on the same trick for years: hide malicious content where traditional email security tools cannot easily inspect it. Password-protected attachments, QR-coded URLs, and redirector-wrapped links have often acted as convenient hiding places for attackers. But it's possible to stop these threats.