Where do those email addresses come form

[Karl]

I occasionally get a spurious email address when filling out the To: box on
an email. The individual and / or the email address does not exist in my
Contacts. Where is it and how do I delete it from my system?

 

[Mary]

You can remove any bad address by navigating to it by using the arrows and
pressing delete. You must use the arrow keys to highlight or it won't work.

 

[VanguardLH]

in message

I occasionally get a spurious email address when filling out the To:
box on
an email. The individual and / or the email address does not exist
in my
Contacts. Where is it and how do I delete it from my system?

Those are the e-mail addresses that you have manually entered before.
If you don't want a particular one, use the up-down arrow keys to
select it and hit the Del key. If you want all those cached nicknames
deleted, go find and delete the .nk2 file.

http://support.microsoft.com/search/default.aspx?&query=outlook+nk2