How to Create a Whitelist in Outlook Express

When you want to be able to only receive email from specific
people, it's called "whitelisting." You can create a whitelist
in Outlook Express by using its Message Rules function. Here's
how:

1. Click Tools and select Message Rules, then Mail.
2. Click the New button.
3. In the list of conditions, check the box labeled "Where
    the From line contains people."
4. Under Rule Description, click the link "contains people."
5. Click the Address Book button.
6. Add the people from your address book that you wish to
    allow to send you mail, then click OK to close the address
    book.
7. Click the Options button.
8. Under "Apply rule if," click "Message does not contain
     the people below." Click OK.
9. Now under "Select the Actions for your rule," either
    check the box that says "Delete it" or, if you want to be more
    cautious, create a folder called Quarantine and check "Move it
    to the specified folder." That way, you can check the messages
    to be deleted in case there is mail there that you want to
    get. [Source: WXPnews]