Whether or not agents are requested to provide candidate contact details (email and/or mobile number) is a configurable option on your system. As a default, agents are not requested to provide these details. Therefore, emails to agent candidates may be sent to the agent only, who is expected to pass on the information to the candidate.
However, if agents are requested to provide candidate contact details in your Recruit system, you can set any email template to go to the candidate (as well as the agent) by checking this box and committing the change:
You can check if you are gathering agent candidate contact details by adding "candidate email" as a column to a candidate view, and checking if it is populated or not for your agent candidates. If it's empty, and you would like to gather candidate contact info, to allow you to communicate with candidates directly, please raise a ticket and ask for this option to be activated.