You can share files from the cloud by adding a link to a message.
In your message, on the Message tab, select Insert Link.
Locate the item or folder that you want to attach and click to select it.
You can choose a file from the drop-down list, browse cloud locations, or insert a hyperlink.
Note: The first time you attach a link to a document that's stored in the cloud, you might be prompted to add a source.