I had a wierd experience using the email "send to Kindle" feature. I tried multiple times to send my kindle the book "You Deserve a Tech Union" and each time it errored and would not import it. I just looked up the book on Amazon and it looks like it's also inaccessible to purchase as a kindle file directly from Amazon which makes me wonder if Amazon is actively preventing it from being loaded onto kindles or if it's a wierd fluke. If anyone has successfully added it to their kindle let me know