Ask HN: what is this? "hnbannedyou@hushmail.com"?

I got this email: "FYI,

All of your comments have been automatically marked 'dead' for the last 22 days."

from the above email address... but here's my questions. I dont have an email associated with this account, so how did whoever wrote this know my email? Secondly, is the above address legit? Why from hushmail instead of ycombinator?

And clearly I'm not banned if I can post this right? What is happening? Spam?