Here are my .mail comments
I agree that more needs to be done with to improve email. However, I don't see any reason why the ".mail" benefit, well, really anyone at all. As far as I can see, this is basically a reverse DNS lookup method. The only difference is an outside company would be handling the verification, and all mail received from them would be considered legit. Why not just leave this issue up to the mail service providers? The .mail domain does not really solve any issues that are not already in place. The really issue here is education.
I am all for adding domains where it benefits a safer, more secure or user friendly internet, however, the .mail is not it. At best all this would do is add more complexity and expense for larger corporations (as there is no real advantage, I don't see smaller firms willing to spend the money to register). Unfortunately, the complexity would be without gain as you would still not be able to block email coming from typical .net & .com addresses as most companies would not be interested in a solution that could easily block emails from legitimate users. This would simply be an email labeling system.
In short, the key is not .mail. The better answer is educating users (especially home cable and DSL users) of good security and setup practices. Oh, and antivirus software!