A network adapter includes circuitry and one or more ports. The ports connect to a communication network including multiple network elements. The circuitry accesses outbound messages that are pending to be sent over the communication network to multiple remote nodes via the ports. At least some of the outbound messages request the remote nodes to send respective amounts of data back to the network adapter. Based on the amounts of data requested by the outbound messages, the circuitry forecasts a bandwidth of inbound response traffic, which is expected to traverse a selected network element in response to the outbound messages toward the network adapter, determines a schedule for transmitting the outbound messages to the remote nodes so that the forecasted bandwidth meets a bandwidth supported by the selected network element, and transmits the outbound messages to the remote nodes in accordance with the determined schedule.