A method, system, and computer program product for publish/subscribe messaging. A subscription is initiated, including designating a subscription queue to which published messages relating to the subscription are to be put. Multiple content-based filtering expressions are defined for the subscription, each of the filtering expressions being defined for a given utilization of the subscription queue. Furthermore, in another aspect, a published message relating to a subscription is received. The utilization of a subscription queue designated in the subscription is checked. A content-based filtering expression defined for the given utilization of the subscription queue is determined. The content-based filtering expression may then be applied.