There are two address books within Outlook that may help you to find a person and their email address. The first is your Contacts List and the other is the Global Address List where you should be able to find the email address of any member of the University.
Find a Contact
When creating a new email, to lookup a contacts name, select the 'address book' icon next to the 'To' field in the top right drop down box select contacts, then look through the contacts you have for the person you are trying to find.
Find a person from the University
When creating a new email, to lookup a member of staff or students name, select the 'address book' icon next to the 'To' field. Start typing the surname, the Global Address book is visible in the large window and this will start homing in on the name as you type, you may need to type a comma and part of the first name if there are several choices. Once you have got to the name you want, double-click the name and it will appear in the To field, and then say OK to exit the address book dialog.