If when you launch Outlook for Mac 2011, you click new message, reply, or forward in and nothing happens, then this article may interest you.
To resolve this issue, Microsoft KB2456873 reccomends you try these methods in this order:
1. Reinstall Safari
2. Download and install the latest Apple software update
3. Validate Fonts
4. Test in Safe Mode
5. Clear Login Items
6. Create a new user account