If you select your Contacts and go to top level where every contact is listed you will find defunct email addresses which you can then delete in the normal way.
Hello Sally,
you can indeed manage all your contacts in the Contacts section.
There is also automatically saved Recipients history which you can manage or delete in Menu>Tools>Settings>Mail>Compose window.
Regards,
Olivia
thanks I did finally discover this by going to top level of contacts (if you have lists that is)
thanks for the reply much appreciated
Sally