Click on the Options heading in the Navigation Pane.
Scroll down to the Privacy and Junk Email Prevention section. Place a check mark next to Filter Junk Email to enable the spam filter.
In the Privacy and Junk Mail Email Prevention section, click on Manage Junk Email Lists. This will take you to a list of "Safe Senders." Safe Senders are people or organizations from whom you want to recieve messages. Adding an address to the Safe Senders list prevents the junk mail filter from blocking mail from that address.
Click the Add button. Enter the address or domain name of the sender you want to add and click OK.