Not natively. There are plenty of add-ins that can do this.:
http://www.slipstick.com/addins/contacts.htm#data

Signature
Russ Valentine
[MVP-Outlook]
> Is there a way for Outlook 2003 to scan all emails and give a list of
> contacts (name and email address) that it encounters along the way (may be
> thousands) so that I can select from the list and add to "Contacts"?
>
> I have lost my Contacts and want to rebuild them from my Inboxes.