Block or unblock messages
When you are in a conversation and want to block messages, select Options >
Block contact.
To block messages from a specific contact in your contacts list, scroll to the
contact in Conversations, Online () or Offline () and select Options > Block
contact > OK.
To unblock a contact, in the IM main menu select Options > Blocked list.
Scroll to the contact you want to unblock, and select Unblock > OK.