See http://www.slipstick.com/contacts/addauto.htm for various ways to save
senders or recipients as new contacts automatically, depending on your
version and configuration of Outlook.
No current versions of Outlook have the ability to add recipients
automatically to your Contacts Folder. Only the long abandoned IMO mode of
Outlook 98/2000 did that. To automatically add the email address of people
you respond to to your Contacts Folder requires code: