Out of curiosity, what's stopping me from using this to sign up for services and having this app mahically keeping their emails out of my inbox, but neatly filed away for when I need it?
Author of Kill the Newsletter! here. First, thank you for your interest. Nothing technically prevents you from using the tool in the way you propose. But I ask you not to, if you can. See https://news.ycombinator.com/item?id=12957555.