Blocking specific email addresses and domains are essential to controlling the amount of junk mail you get in Microsoft Outlook 2010 or 2007. You can add email addresses and domains to the block list by using the following steps:
1. Outlook 2010 users select the Home tab, select Junk > Junk E-mail Options. Outlook 2007 users select Tools > Options > Preferences > E-mail > Junk E-mail.
3. Click the Blocked Senders tab.
4. Click Add.
5. In the Enter an e-mail address or Internet domain name to be added to the list box, enter the name or address that you want to add. You can add entire domains or just an email address as follows:
6. Click OK when you are done.