Hopefully you don't have too many contacts that you want this to happen with
but you can go into each contact and change the "Display as:" field. This
field is right under the Email address field. It will probably show the
persons name. All you need to do is copy/paste the email address into this
field. When you highlight and "copy" the email address right above it and
then move your cursor to the "Display as" field and right click, it should
highlight the name, when you click "Paste", it will replace the name with the
email address. Then when you send that person an email, it will show the
email address rather than their name in the "To:", "C.C." or "B.C.C." line.
Oooops. After I typed all of that, I realized I misread your post and you
were looking for incoming mail, rather than outgoing mail but the above
information may still be of assistance. Read on.
To see the email addresses in the "From" field of an email that has the name
showing would require you to open the header information of the email. With
Outlook, this is done by right clicking on the email file (it does not have
to be opened) and choosing Options. In the Message Options pop-up, you will
see the email address of the sender. If this sender is already in your
contacts list, then you may be able to change the view as described above and
the emails will show up from "(e-mail address removed)" rather than John Doe. You'll
have to experiment with this by changing the Display As in one of your
frequently received emails which you alread have a address book contact
already.