Over time, Outlook builds up quite a collection of email addresses that it “helpfully” assists you with when you start to type a name in the To field. However, people move on, change email addresses, or no longer qualify as someone you want or need to email. Here’s how you can get rid of those names that just clutter things up.
Here’s an example of what I see when I start to type in my last name in an Outlook email:
In this case, I don’t want to see that last one, as it was for a test scenario. If I hover over that name, a black X appears to the right of the name. If I click it, the name is deleted from the Autocomplete list, and I’ll never see it again!
One Minute Office Magic 