Some junk mailers change the sender name automatically for each junk message. So if for example you add the full e-mail address "firstname.lastname@example.org" to your Blocked Senders List today, you may receive spam from "email@example.com" tomorrow. This can be highly annoying, but there is a way to stop it.
The part of an e-mail address after the @ sign is called the domain. It identifies the computer or network on the Internet that was used to send the message. For example, if you add the domain name "@adatum.com" to your blocked list (as shown in the picture), then all messages arriving from any sender at "@adatum.com" will be sent to your Junk E-mail folder.
If, on the other hand, the domain "@adatum.com" sometimes appears on messages to or from your customers or associates, then obviously you don't ever want any of those messages going to the Junk E-mail folder. In that case, include the domain name on both of your safe lists — and then all messages from or to that domain will go straight to your Inbox. (Be sure to include the @ sign!)
Reminder For your Safe Senders List only, there's a command on the Junk E-mail submenu for adding a domain.