Messages always send to user and never to email

In Sitellite control panel, when you compose a message, you can choose recipients among the list of users, or enter an email address. But the Recipients widget returns a comma separated string, which is passed to send() function in cms.Workspace.Message . Then, it takes all the values and use them as if there were all user. Do we want to be able to send email messages from the control panel? If yes, we should check whether the values are usernames of email addresses. If not, we shouldn't have the email option in the cms.Widget.Recipients widget.