If the Antivirus & Antispam service has already been ordered and activated for the 5 domain accounts, it will automatically operate also for the other accounts created with the unlimited email service. However, you will need to configure the mail client as indicated in the “Antivirus & Antispam” section.
Furthermore you will be able to customize the antispam filter for each account, as indicated in the article “Customization of the Antispam filter