It's a known enhancement request, which hasn't been implemented yet, unfortunately. I hope, we will get the chance in one of the next versions.

Why was this IMPORTANT feature left out? How does the mail account owner control the emails being sent from all the different portals using his account? These portals could be independent web sites whose owners could be abusing any module which sends out emails. They could be sending out spam, junk mail, mass emailings and the poor dnn installation owner, whose email account is being used by possibly hundreds of users, might be getting warnings from his ISP because of possible abuse which he is not responsible for. All he is responsible for was creating the portals. Even if he has logging turned on at the mail server level AND if the ISP agrees to turn it on, he would not know who was the source of any message. The feedback module is an example.

Doesn't this concern anyone or am  I missing some configuration?