If your Outlook is not updating email addresses, it is probably set to cached exchange mode. Here is how to fix that:
1. Click on File at the top left.
2. Click Account Settings.
3. Click Account Settings.
4. Click Data Files.
5. Click Settings.
6. Click Advanced.
7. Uncheck the Cached Exchange Mode.
8. Click Apply.
9. Click OK.
10. Click Close.
11. Close out of Outlook.
12. Reopen Outlook.
a. Email addresses should be up to date.