Continuing on in my rebuttals to the reviewers who refused my paper (which I believe is my right... if they can review it and refuse then I can disagree with their reasons for refusal), I'd like to move on to the second reviewer.
The definitions given in Sections 2 and 6 and the metrics given in Sections 3-5 lack novelty. No references to the anti-spam literature are given.
It appears restrictive to limit spam to commercial mail. E.g., there is also political and religious spam.
It is true that the definitions I give in sections 2 and 6 are not new. Yet it seems that if you post to a user forum that these are what define spam and grey mail, piles of people will disagree. I defined spam as unsolicited commercial email... but I expanded that definition as "mail that an average user would not want to receive. This disqualifies newsletters that a user has opted into but no longer wants to continue receiving."
I didn't want to rat hole on the definition of spam. Sure, it could be unsolicited commercial mail. The point is that we all know what spam is when we see it, but we also need to make sure about what is not spam. We have piles and piles of end users who have signed up for newsletters that they don't want anymore. This is not spam, and that was my point. All unwanted mail is not spam. My whole point was to be holistic about what we are dealing with.
This ties into the second comment. There is political and religious spam but my point wasn't to limit it only to commercial spam. If you get political rants unsolicited, the same with religious rants, then that is spam. For the most part, spam is spam and if you didn't ask for it and the sender didn't have permission to send it to you and they sent it to a lot of people, then it is spam. I didn't go into greater details and explanation because I only had three pages.
For metrics and measurements purposes, we need to know what we are measuring and what we are not measuring. Not everyone agrees but we can get a broad consensus.