Make Outlook your default application for e-mail, calendar, and contacts
You can make Outlook open automatically when you click a link to send e-mail (sometimes called a "mailto" link) in a document or on a Web page. Similarly, you can make events and contacts open in Outlook when you open them from the Finder or the desktop.
On the Outlook menu, click Preferences.
Under Personal Settings, click General .
Under Default application, click Make Default.