Requirement is to send friendly reminder to two dunning contacts that is been set at the customer le

I Had set the two dunning contact at the customer account level, one is primary, Now when the friendly reminder work item is sent i see its been only to sent to the email of the Primary dunning contact person and it does not go to another person who is also defined for dunning contact.

Basically the background is we would want the dunning contact also to be sent to the other person so that the activities of the collector can be kept tab of it.