When creating an campaign activity of the activity type email, their is the possibility by creating the emails to set the owner of the email on the value of the owner of the contact, to which the emai is send to. But the sender of the email can always be one fixed user. Goof for that case, when a fix sending address is needed, like 'info@...". But very bad, when a personalized speech to the contact is needed. Then the sender of the email should be the same person as the owner of the contact. I would suggest that there will be the two possibilities to choose, for instance: if the sender of the emal is not set, always use the owner of the contact; if the sender of the email is set, use always this user as sender;