A story recently broke on 404 Media that made deliverability experts everywhere cry a little inside: YouTube channel Channel 5 admitted to handing a CSV file of its email subscribers over to a third party so that person could market a new product to them.Putting aside the specific names and political figures involved (which are irrelevant to the underlying email mechanics) this incident serves as a prime example of what never to do with your email list.If you own an email list, hand-delivering a .csv file of your subscribers' contact information to a third party is fundamentally, egregiously stupid. It...