Outlook.com Doesn't Play Well With Android Mobile
 

Microsoft has acknowledged that its rollout of the Outlook.com email service has hit a few bumps in the road, specifically the inability to open Office attachments in the cloud with Android devices. Microsoft is looking into the problem for a fix. The issues you are running into are limitations that are specific to the Android mobile browsing experience and the Office Web Applications. Microsoft is aware of them and the team continues to use this feedback to improve the Outlook.com Preview on all modern devices.

http://www.hardocp.com/news/2012/08/...ndroid_mobile/