Workflow Step fails and retries entire workflow 11 times

Hi,

we have a registration workflow that has two steps:

1. Send email to admin
2. Send email to user

The problem is that sometimes the mail server doesn't like the user's email address and refuses to send the email, throwing an exception in that workflow step. In the logs I can see the exception and I can see that AEM restarts the entire workflow (also sending emails to the admin). My question now is, why does AEM restart the entire workflow and not just the step that failed?

Thanks,

Paul