I've recent received this email myself. My conclusion is that the email is legitimate. I've not based this on the content or headers of the email, which can be faked by advanced scammers. I've based this on the fact that my Amazon password has become invalid, at the same time. A scammer wouldn't usually be able to do that. A couple of the answers also mention this.
The problem with the question is the voting on answers. The "it's fake" answers get upvoted and the "it's legit" answers get downvoted. I can see why - there's a large "tin foil hat" brigade on this site, who have just enough knowledge to be dangerous. I've often thought the voting on questions and answers is completely out of whack. But this is the first time that it's ended up promoting wrong answers.
I realise I could ask OP to accept one of the "it's legit" answers. However, he has answered his own question, and spread more confusion, so I don't think asking him to do that will help.
Not quite sure what to do here, can mods accept an answer?