You can add this feature to emails you REPLY (Tools, Options, Send) to, but I don't think it can be done when creating a new email. You have to tell OE to add it.
I posted this message a few days ago on the MS Office site but got no response - maybe someone on this very alive forum can help me.
Using Office XP. What I would like is for Outlook to automatically add the address of mail that I send, to my address book. I seem to recall such an option being available in Office 2000 but cannot locate it in Office XP. Any advice?

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