What is the exact procedure for uploading / backing up files to this online account ?
If youve setup an account, you cannot upload files manually. After each synchronisation, it will automatically backup the data online. You may check if the backup was succesfully uploaded after the synchonisation by connecting to your online service and by clicking on the “browse” tab,or by connecting to your online files through the web https://apps.dmaileronline.com/l/login.