There’s nothing nefarious going on with the email system here — that’s just a standard reply notification. I’ve edited out the email headers to protect your email.
This was just a standard spam post by a spam user (us mods can still see it). It was posted at 2:30am, flagged at 3:20am and removed by 3:38am EDT. The user doesn’t exist anymore because we banned them with a vengeance. When you see spam, flag it! 
We have been seeing more spam lately — and while we can clean up the site afterwards, we can’t un-send email notifications unfortunately.