A have new problem that has appeared in my Mac Mail. When I type a frequently used email into the 'To: line' it populates the correct name but with 8 different email addresses not associated with that name.

A have new problem that has appeared in my Mac Mail. When I type a frequently used email into the 'To: line' it populates the correct name but with 8 different email addresses not associated with that name. I have gone to the window pop-down to 'previous recipients' and deleted that addressee as well as all the email addresses it is assigning to that name. I have also deleted the account entirely from my address book. I have have run repair permissions and also full defrag in iDefrag. Still the problem persists. Any suggestions?