Having More Than One Identity in Roundcube

I have a number of emails used for the business (My Personal, an Order_Received and a Customer_Service) in which I sign in and out of regularly. On occasion, I'd like to send an email from one address showing the address of one of the other addresses. (If that makes sense)........

I am looking for something like Outlook that allows the author to pick from several email addresses.  Roundcube themselves state a person can add any number of "Identities" to an email address "Unless restricted by the server administrator". 

Can several email Identities be set up? If so, how?