While you can't prevent someone from sending a message to you, you can block up to 500 email addresses or web sites. All incoming messages from these blocked addresses will be automatically deleted, without bouncing back to the sender or going into one of your mail folders.

1. Sign in to your Yahoo! Business Email account.
2. Click the "Options" link.

   
   Business Email Options Link

3. Select "Mail Options" from the Options pull-down menu.

   
   Business Email Options Pull-Down Menu

4. Click the "Blocked Addresses" link located in the left column.

   
   Business Email Blocked Addresses Link

5. Add the address you would like to block to the "Add a blocked address" field and click the + (plus) button.

   
   Business Email Add Address to Blocked Addresses.

   Tip: To block email messages from an entire domain (for example, baddomain.com), enter the domain in this field.
   

To remove or unblock an address or domain from your list:

1. Select the entry to remove, then click the button with the trash can icon.

   
   Business Email - Remove Email Address from Blocked List

2. The address or domain disappears from your list of blocked addresses.