There are two ways to attach files.
Click the Upload a File button under the subject line to browse your computer or network for files. Select your file to attach it to the message.
Firefox, Chrome and Safari users have the added option to 'drag and drop' files from their computer or network locations. Locate the file in your Explorer or Finder window and drag it to the Secure-Mail™ message, release the mouse button in the pink area to initiate the upload.
When the file finishes uploading the filename will appear in the upload area. To un-attach a file click the white 'X' in the red box icon to the right of the filename.