How to edit recent address in kmail

If I manually add an email address, it will appear in the recent address’s list. How can I edit this list so that I can add them to my contacts.

KDE 4.3.5, KMail 1.12.4

I cannot find a way to add a completely new email address other than by creating a new contact. I normally right click on a new email address in an email and select Add to address book which automatically adds the address to my list of contacts. I am using 1.12.2.