Yahoo! Messenger

• 1). Click the "Messenger" menu at the top of the Yahoo! Messenger window and click "Preferences."
  
  
• 2). Click the "Ignore List" category at the left side of the preferences window.
  
  
• 3). Click the name of the contact you want to unblock in the ignore list and click the "Remove" button.
  
  
• 4). Click the "OK" button at the bottom of the preferences window.
  
  

Yahoo! Mail

• 1). Click the "Options" link at the top-right corner of the Yahoo! Mail page and click "More Options."
  
  
• 2). Click the "Spam" category at the left side of the options page.
  
  
• 3). Click an email address in the list of blocked email addresses and click the "Remove" button.