tl;dr: If you are sending messages to RabbitMQ to communicate one application to another, you are not doing Event Sourcing. You’re just doing messaging ;)
In the last two months, I’ve seen different nice talks using DDD, CQRS or Event Sourcing in the talk title. However, after watching the content, I think there are some general misunderstandings about some of the concepts. The most important one, in my honest opinion, is calling Event Sourcing to sending messaging to other applications using a broker. Event Sourcing is not about that. Let me explain a bit more.