Customer-specific spam policy triggered and quarantined genuine Inbound emails from genuine domains. Some emails get delivered to the recipient and others get caught by customer-specific spam policy.
SMG version 10.7.3
Once a message is submitted for false-positive, then the rule appears to be properly killed. Next "missed spam" submission, appears to re-activate the previously killed rule (as well as create the expected new rule).
This problem is identified and has been fixed.