Dean wrote:

Often, I will need to search my sent items for messages I may have
sent to a particular person and, not so often, I can't find some,
after sorting by name. I then realize that the name has dual
listings, such as 'Joe Jones' and . I assume
that this happens because, at some point, I added that person to my
list of contacts, as 'Joe Jones'. Is there any way to merge the two
names, so I don't have this problem again?

The initial entry probably depends on what the sender used as his "friendly
name" (what would be the equivalent of the "Your Name" field in your account
properties). If they didn't set that value, then you'll see their email
address in the To field as the "Display As" value when you reply. If you've
subsequently added that person as a contact and have set their Display As
field to just their name, then new messages you send will, as you say, have
the Display As field showing in the To field.

You can always update the value the To field shows for those recipients for
whom you've added to your contacts. Open the message and double-click the
recipient. This will open an "E-mail Properties" dialogue and you can
modify the "Display name" field there. Click OK, close the message, and
click Yes when asked if you want to save the changes.
--
Brian Tillman