Cloud Mail has enhanced email filtering mechanisms. Therefore unwanted emails are blocked by the system before they delivered to your Inbox. All these happens without needing to teach the system for which emails are unwanted and which aren't.
In addition, Cloud Mail is equipped with antivirus and every single email that arrives is being scanned for viruses and malwares and then forwarded to mail server in order to deliver it in the appropriate mailbox. So you are protected from viruses and malwares included in your emails even if you don't have other antivirus solution.