You might try a little add on utility from mapilab called ADD CONTACTS. Below is from their program description:
Add Contacts automatically adds e-mail addresses to the contacts folder when you reply to a message and/or send a new message. This will help you avoid losing addresses of people you correspond with. Moreover, the collected addresses can be used for mail filtering. For example, you can use the Rule Wizard to have messages from certain senders (whose addresses are in the address book) placed in a separate folder to ensure that their message will be dealt with greater priority and no important messages will be lost with deleted spam.
You can also instruct the program to analyze all of your old sent emails (or archived emails in any folder, actually) and automatically add the email addresses it finds into your outlook contacts folder, or a contact folder of your choice. It comes with a 30 day trial and $15 to keep using it after that.
The website is at
http://www.mapilab.com
Hope that helps.