We do a lot of testing for recurring deliveries sent from workflows, which requires us to make a single-send delivery for profile substitution. This results over time in a large amount of test deliveries in pending status, which can suck up resources, unless we want to delete the test deliveries when we're done testing and then create them again later. We'd rather avoid that approach if possible. Is there a way to cancel a pending delivery so that it is no longer pending? Looking at the UI I'm not seeing a way. I tried stopping the workflow and also tried disabling the delivery, but neither worked.
Have you tried creating a workflow with an update activity to change the status on the pending delivery to the recipient (in the broadlogrcp table) to canceled?