All Agents with default roles in Freshdesk will be able to delete tickets. However, if your account is in the Estate plan/ Forest plan, you can create Custom Roles for agents who shouldn't be deleting tickets. To be notified if the tickets are deleted by specific agents, you can create an Observer rule "When an action performed by..." "agent". "Involves any of these events" "Ticket is deleted and Marked as Spam", then notify one of the Admins or Supervisors about it.