How do I set up multiple Outlook users under the same computer login but have Outlook ask for their password each time Outlook is opened?

Currently we have only one user profile to log in to our MAC per our boss. I would like to open outlook by using the program that is installed on the computer but if I add my account anyone that logs in using our one user profile will be able to see my emails. Can that be changed?

Thanks,

Saul Miramontes