A volume constraint uses the Return any action that does not exceedconstraint mode.

CUST-05 receives the Diamond card offer because it is the only action that does not exceed the volume constraint for the email channel. The Silver card offer has already reached its limit of 2 emails per day, so it is not eligible for CUST-05. The volume constraint mode Return any action that does not exceed means that any action that meets the eligibility and suitability criteria and does not violate the volume constraint will be returned, even if there are other actions with higher priority or propensity. Verified References: Certified Pega Decisioning Consultant | Pega Academy, Volume constraints