Besides being able to configure separately which email server different apps from an Outsystems factory can use, which is already an Idea: https://www.outsystems.com/ideas/305/multiple-email-server-configuration-support/

I also think it would be useful to separately configure the "Test List Addresses" field, so that different apps in the same factory can send test emails to a different subset of emails:

If the server idea takes longer to implement, and the separation of the "Test List Addresses" field takes less effort to implement, I believe it would be a quick-win to implement this feature first.