I’ve never understood how Outlook decides what names appear in their type-ahead drop-down list. I’ve had two Kevin’s in there: one I send mail to a number of times a day, another I sent to once over a year ago. Because of their last names, never-again-Kevin appeared first in the list, and all-the-time-Kevin was second.
I asked my IT guru to find out how to delete names from the list. I thought it would require poking around in some address book, removing entries. Nope. It’s dead simple: when the list pops up, use the arrow keys to select people you don’t want, and hit the delete key! They’re history!