unwanted adresses in contactlist

Hello,How can I suppress the addition of unwanted adresses in my contactlist. When sending to or receving from an incidnetsl contact (a shop or so) that address is added to my contactlist. How can I suppress that?
Piet de Geus

eM Client keeps a history of recipients who are not in your contacts, to whom you have previously sent  a message.

You can edit the list in Menu > Tools > Settings > Mail > Compose > Recipients History.