How to get notified about error 500 with Amazon Web Services

I set up an application using elastic beanstalk and I would like to receive an email everytime an error 500 is caught.

I'm able to receive an email using load balancer HTTPCode_Backend_5XX alarm in CloudWatch service but what I really want is to receive the error message.

There is a ton of services out there and I'm not sure which one to use to get a solution to my problem.