Put other people in copy on an email the agent sends

When the agent sends an email, we want to put other people in copy on that same email, the way a person does in Outlook.

Today the agent can send to one address only. Extra people can be named in the text of the email, but they never receive it. In a recent case, an email went to a service desk address and the client contact was meant to receive a copy of it. The only option was a second, separate email.

What we want: a field for copy addresses, so everyone is on the same email and can reply to all. The copy addresses should also appear in the approval request the technician sees before the email goes out, and in the record of what the agent did.

Raised by Mike Yersh at M2 TechNet.