Once you have typed in a person's name from an address book/contacts once, it will auto complete from there on out. 

If you are typing in a recipient's name from an address book for the first time, it won't automatically recognize them in the "To" field.  

1. Once you have typed in their name, select Check Names from the Names box in the ribbon. If there is only one match, it will underline their name in the "To" field signifying that it is good to go.

2. If there are multiple matches, it will then present you with a popup window that contains a list of possible matches. Select the correct one and click OK. Please note that the Parkland Global Address Book contains the names of students as well so you may get multiple hits for that reason.

3. Outlook will then add that person automatically to the field.  The next time you address a message to that person, it will remember and auto complete for you.