Subscribe to, Unsubscribe from Channels
To subscribe to a channel, open it and click . The channel will be added to your contact list and will display a flag to notify you of new unread messages.
To unsubscribe from a channel, open it and click . You will stop getting notifications and the channel will be removed from the list.
To configure notification preferences of a channel you're subscribed to, open it and click the small arrow on then choose the desired options: