To stop receiving email from someone, you can add his or her email address to your blocked senders list. Outlook automatically moves any new mail you receive from this person to the Junk email folder. When you want to receive mail from this person again, you can remove his or her email address or domain from your blocked senders list.
Block a sender
In the message list, select a message from the sender whom you want to block.
On the Home tab, click Junk, and click Block Sender.
Outlook adds the sender's email address to the blocked senders list.
Note: You can restore any of the mail that is in the Junk email folder. Click the message that you want to move to the Inbox folder, and then on the Home tab, click Junk, and then click Not Junk.
Unblock a sender
On the Home tab, click Junk, and then click Junk Email Preferences.
On the Blocked Senders tab, select the email address or domain you want to unblock, and then press the Delete key.