There isn't a lot here that you can't get for free with services like mail-tester.com. I was interested in the idea of downloading an 'audience' list to send your email to, so you can test deliverability to all the various mail providers. But in reality the 'audience' is made up of only mail accounts. Perhaps in the future this feature will access outlook, Zoho, yahoo, etc and then it might be useful, but it's not there yet.