abstract class BaseMessage
{
    public abstract void OnNewMessage(Message message);
    public void Send(Message message)
    {
        //Sending, i.E. HTTP, RabbitMQ, whatever
    }
}

class MessageUse1 : BaseMessage
{
    public override void OnNewMessage(Message message)
    {
        //.. Do whatever
    }

    public void ShoudSendMessage(Message message)
    {
        Send(new Message());
    }
}