As for “X is a spammer” I have heard people say that about lots of companies. I mean, there are people who have accused me of being a spammer because I actually work for companies who send mail that the accuser does not like. I believe the word itself is meaningless and the accusation likewise. If your mail is being delivered, then you are good. If your mail is not being delivered, then there is something wrong. If that something is that you are listed on Spamhaus, then you need to deal with them and fix the underlying problem with your mail.

I have read the post you linked to, but I do not see anything in there about a e360 alleging there was a DNS denial of service attack from Comcast. The only mention of DNS is in the quote from Wikipedia describing that as one particular type of DoS attack. In the filing itself the only allegation of a DoS is that Comcast was keeping connections open for 5 hours.

As to Spamhaus and filtering I think they are very erratic in their decisionmaking. Your definition nailed it. There are a ton of companies who send email that users don’t really “ask” for but they don’t end up on Spamhaus list (bigger, more established companies). On the flipside, merely sending unsolicited email is NOT a CAN-SPAM violation. The email has to be misleading. That’s why I always raise my eyebrows when someone says that “X is a spammer because Spamhaus says so”.

I can see why you think companies are erratic about filtering decisions, but I think that filtering decisions may look erratic to the outside because most legitimate senders do not see the tons and tons of illegitimate spam and viruses that ISPs are battling against. The filtering criteria implemented by larger ISPs are usually done in response to some specific spammer behaviour.

As for Spamhaus, their criteria are clear - do not send mail to people who did not ask to receive it. The ISPs that rely on Spamhaus listings do so because Spamhaus philosophy fits their own, they believe the listings Spamhaus listings are accurate and, most importantly, their user base does not complain about the filtering.

In my experience, senders and receivers speak very different languages and what is clear language to one side is gobbledegook to the other. I often describe my job as a delivery consultant as “interpreter” that is I speak both sender and receiver. I think a lot of the confusion and misunderstanding about what receivers are doing stems from this language difference.

I looked around for the Fish Blog post, as this was the first I have heard about accusations of Comcast and a DNS attack against e360. I did not find the blog post, so if you have a link, I am interested in seeing what DNS attacks e360 is alleging.

Anyway, your point is well taken. Also, I came across a post on the Fish Blog about a supposed DNS attack undertaken by Comcast against e360. Not sure what to make of it (and I’m skeptical), but this could tweak the Section 230 analysis somewhat.