Here’s a protip: Save your contacts!  Should your computer need to be reformatted or upgraded, you run the risk of losing the contacts you email on a frequent basis.
Why is this?
When you start typing a name in your address field and Outlook offers completion suggestions, that’s called auto-complete – and that does NOT get backed up anywhere.
Solution?
Copy that person into your address book.  When you get a new person’s email, right click on their name in your outlook, and choose “Add to Outlook Contacts”
It’s really that simple: plus it takes away [some] the woes of your IT Administrator.
-Dexter