A method, apparatus, and computer instructions for filtering and prioritizing instant messaging threaded conversations in an instant messaging system based on thread content. The instant messaging client analyzes an incoming message to determine the thread subject. Based on the thread subject analysis, the client determines the priority level associated with the incoming message. The message is then delivered and displayed to the recipient according to the priority level. The present invention also allows a participant initiating a thread of conversation to override filter settings on a messaging client. The authority to override settings may be predicated on an external list, such as a corporate telephone directory. As a result, the participant, having some authority or rights to override the recipient's instant messaging settings, may be allowed to conduct a messaging session with the recipient.