A blacklist is a list of accumulated e-mail addresses which have unwanted emails. The whitelist is the opposite of blacklist, the e-mails to the registered email addresses will necessarily be accepted, regardless of whether an email has been classified as spam.
In easyname you have the opportunity for each mailbox individually determine blacklist or whitelist rules. Click on [Web Hosting] and then "e-mail accounts. In this view, all your mailboxes are displayed. Go ahead and click on the Edit icon for the desired mailbox, and immediately thereafter to "blacklist / whitelist Set" at the bottom of the page. Now you can specify an email address in the Whitelist box whose emails are desirable and / or provide an email address in the blacklist box whose emails are not desirable. Of course, you can specify several email addresses to spam the personal behavior to optimize.
If you want to list a whole domain, you have to use following syntax: *@domain-example.com