Bypassing
Overview
Could Email Security can be configured to bypass processing in certain conditions to provide continuity of the email flow.
For configuration details see Configuration/Policy.
Risks
If an email gets bypassed, then the original, potentially harmful email is delivered to the original recipient.
Disclaimers
Could Email Security should be configured to append a disclaimer to the email when it is bypassed. This disclaimer can inform the user about the fact that the email was bypassed and that it may contain harmful content.
For details see Configuration/Policy.

The disclaimer warning about bypassing rendered in an email:

Monitoring
Bypassing exposes the email system and the whole organization to higher level of risk. Bypassing can be monitored on the Dashboard via the Risk and Risk summary widgets.
For details see Dashboard.

If the number of bypassed emails is raising, that indicates a potential problem in the system and the raised level of security risk.