To make a file available for download via a Published page use the Publishing feature, you must be a user in the Publishing Users group to get access to this function.
Once you have submitted your file for publishing, a user belonging to the Publishing Administrators group will need to approve publishing of the file.
To publish a file from the Outlook Add-in into Thru :
Select the file is question and from the right click menu select Publish
A Send Publishing Request window will appear, select the Collection that the file needs to be published under