Go ahead – appear offline to someone, permanently. They won’t be able to send you any chat messages!

Click Block Sender anytime one of your Contacts with whom you don’t want to chat tries to start a chat with you. It’s a button along the top of the Chat tab. See it?

You can also go in and block them right now:

1. Click the down-arrow on the right end of the Compose button and select Chat to open a conversation tab.
2. In the To: field, enter the name of the person you’d like to block.
3. Now, in the toolbar along the top, click Block Sender. That’s it!

The same button works for anyone who’s not in your Contacts folder. But with them, a dialog automatically opens up first, giving you your first opportunity to block. If you close the dialog without blocking them, and then decide you want to block, that’s fine too: click Block Sender in the toolbar, anytime.

Yahoo! Messenger users: If you want to block a contact who’s in your Messenger buddy list, you’ll first have to remove them from your buddy list in the Messenger client.