With this week's release you can re-use any email in multiple Workfront instances. In the past you've needed to create a unique email for each Workfront instances. Today, right now, you can use the same email in as many instances as needed. We are still working on extending this to Proof. This is a prerequisite for eliminating case sensitivity for email addresses and many more improvements that will be coming with Enhanced Authentication. Melinda Layten Technical Project Manager - API and Integration Workfront