Monitoring user availability to perceive communications received across a network includes determining the existence of activity at a first communication device and accessing a presence rule record storing presence rule data relating the determined existence of activity at the first communication device to an availability of an intended recipient to perceive communications over a second communication device. The presence rule data is applied to the determined existence of activity to assess the availability of the intended recipient to perceive communications over the second communication device. Other entities are informed of the assessed availability of the intended recipient to perceive communications over the second communication device.