Good question! The engine handles this at two levels:

Auto-detection: It scans for transactional signals ("reset your password", "order confirmation", OTP codes, etc.). If it finds 2+, it automatically downgrades the missing-unsubscribe penalty to zero.

Explicit declaration: Callers can pass `emailType: "transactional"`, which fully exempts from both unsubscribe and CAN-SPAM physical address checks.

The compliance rules (unsubscribe, physical address) get exempted because they don't legally apply to transactional mail. But deliverability rules (image ratio, hidden text, deceptive links) stay active intentionally. A transactional email that's 100% images is still a deliverability problem regardless of type.

In practice, well-crafted transactional emails rarely trigger those remaining rules since they tend to be simple, text-forward templates.