Testing Web Services API Triggered Campaigns (w/o Sandbox or Workspaces)

The problem that I'm having right now is figuring out the best method to test our transactional emails. We did not purchase a Marketo Sandbox environment, nor did we purchase workspaces/partitions. Our QA team tests the code/emails in our testing and staging environments before they roll the code live, and that is where the problem is. Once it is live, obviously testing it is easy, but when they are in staging and testing they do not receive any emails... Unless I create an API Staging account in Marketo for their email address and then approve that email address... But, they use hundreds of different email addresses during testing.

Anyone have any ideas?!