To restrict the number of recipients in web messages sent through hr help desk and case management

Summary:

To restrict the number of recipients in web messages sent through hr help desk and case management

Content (please ensure you mask any confidential information):

Hello Team,

As the title states, we are trying to restrict the web previlages/conversation previlages of the mails which are sent using web messages. We have granted conversational previlages to employees via a custom roles but we wish to restrict the recipient list when the response is being sent from the employer by preventing them from adding other employees.
Kindly help us with this as we are in the closign stages of UAT and this is a critical issue for us and if this is not fulfilled the production won't go live without this feature.