Basically, a poller is needed for queueChannel1 and spring integration can move the message to queueChannel2 afterwards.

@Bean
public IntegrationFlow testflow11() {
    return f -> f.channel("queueChannel1")
            .handle(new GenericHandler<String>() {
                @Override
                public String handle(String payload, MessageHeaders headers) {
                    System.out.println("[testflow11]: Processed " + payload);
                    return payload;
                }
            }, e -> e.poller(Pollers.fixedRate(0).maxMessagesPerPoll(-1)))
            .channel("queueChannel2");

}