An often claimed benefit of mobile agent technology is the reduction of communication cost. Especially the area of information filtering has been proposed for the application of mobile filter agents. However, an effective coordination of agents, which takes into account the current network conditions, is difficult to achieve. This contribution analyses the situation that data distributed among various remote data servers has to be examined with mobile filter agents. We present an approach for coordinating the agents' employment, which minimizes communication costs. Validation studies on the possible cost savings for various constellations show that savings up to 90% can be achieved in the face of actual Internet conditions.