Get add-ins for Outlook for Mac
Select See more items (…) in the toolbar and select Get Add-ins.
You can search for add-ins by typing a keyword in the Search box and pressing the Return or Enter key.
When you find the add-in you want, select the Add button.

Hope You Find This Useful,
Peter

Use mozilla thunderbird

http://www.mozilla.org/thunderbird/

It works on mac and it's really powerfull with addons