Hi,
If you are only going to use the images hosted on AEM, ensure they are available in the publish environment. Then, you can reference them in your emails without needing any additional connection. I apologize if you meant a different type of integration or connection, if so, you could explore if this approach could be helpful. Basically just rely on HTTP calls, so as long as there is an API in salesforce for your use case, you should be able to use this: https://www.oshyn.com/blog/aem-and-salesforce-integration
Hope this helps
Esteban Bustamante