In the most recent snapshots, the nullability constraints for RabbitMessageOperations.convertAndSend(…) have defined non-nullability for the parameters. However, the implementation code delegated to (RabbitTemplate) ultimately allows for null parameters (in Rabbittemplate.send(String, String, Message, CorrelationData)) to default the null values based on values configured on the template. It would be nice if the higher-level operations would allow passing in null as well, so that their clients can make use of that defaulting.