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Fight Spam With Nolisting
An anonymous reader writes with the technique of Nolisting, which fights spam by specifying a primary MX that is always unavailable. The page is an extensive FAQ and how-to guide that addressed the objections I immediately came up with. From the article: "It has been observed that when a domain has both a primary (high priority, low number) and a secondary (low priority, high number) MX record configured in DNS, overall SMTP connections will decrease when the primary MX is unavailable. This decrease is unexpected because RFC 2821 (Simple Mail Transfer Protocol) specifies that a client MUST try and retry each MX address in order, and SHOULD try at least two addresses. It turns out that nearly all violators of this specification exist for the purpose of sending spam or viruses. Nolisting takes advantage of this behavior by configuring a domain's primary MX record to use an IP address that does not have an active service listening on SMTP port 25. RFC-compliant clients will retry delivery to the secondary MX, which is configured to serve the role normally performed by the primary MX)."
YASIGFINFE (Yet Another Spam Idea Good For Individuals, Not For Everyone) - Spammers will change their techniques to be more RFC compliant as soon as (if) Yahoo, AOL, Hotmail, Gmail adopted this method.
Your post advocates a
(x) technical ( ) legislative ( ) market-based ( ) vigilante
approach to fighting spam. Your idea will not work. Here is why it won't work. (One or more of the following may apply to your particular idea, and it may have other flaws which used to vary from state to state before a bad federal law was passed.)
( ) Spammers can easily use it to harvest email addresses
( ) Mailing lists and other legitimate email uses would be affected
( ) No one will be able to find the guy or collect the money
( ) It is defenseless against brute force attacks
(x) It will stop spam for two weeks and then we'll be stuck with it
( ) Users of email will not put up with it
( ) Microsoft will not put up with it
( ) The police will not put up with it
( ) Requires too much cooperation from spammers
( ) Requires immediate total cooperation from everybody at once
(X) Many email users cannot afford to lose business or alienate potential employers
( ) Spammers don't care about invalid addresses in their lists
( ) Anyone could anonymously destroy anyone else's career or business
Specifically, your plan fails to account for
( ) Laws expressly prohibiting it
( ) Lack of centrally controlling authority for email
( ) Open relays in foreign countries
( ) Ease of searching tiny alphanumeric address space of all email addresses
(x) Asshats
( ) Jurisdictional problems
( ) Unpopularity of weird new taxes
( ) Public reluctance to accept weird new forms of money
( ) Huge existing software investment in SMTP
( ) Susceptibility of protocols other than SMTP to attack
( ) Willingness of users to install OS patches received by email
( ) Armies of worm riddled broadband-connected Windows boxes
(X) Eternal arms race involved in all filtering approaches
( ) Extreme profitability of spam
( ) Joe jobs and/or identity theft
( ) Technically illiterate politicians
( ) Extreme stupidity on the part of people who do business with spammers
(x) Dishonesty on the part of spammers themselves
( ) Bandwidth costs that are unaffected by client filtering
( ) Outlook
and the following philosophical objections may also apply:
( ) Ideas similar to yours are easy to come up with, yet none have ever
been shown practical
( ) Any scheme based on opt-out is unacceptable
( ) SMTP headers should not be the subject of legislation
( ) Blacklists suck
( ) Whitelists suck
( ) We should be able to talk about Viagra without being censored
( ) Countermeasures should not involve wire fraud or credit card fraud
( ) Countermeasures should not involve sabotage of public networks
( ) Countermeasures must work if phased in gradually
( ) Sending email should be free
( ) Why should we have to trust you and your servers?
( ) Incompatiblity with open source or open source licenses
( ) Feel-good measures do nothing to solve the problem
( ) Temporary/one-time email addresses are cumbersome
( ) I don't want the government reading my email
( ) Killing them that way is not slow and painful enough
Furthermore, this is what I think about you:
(x) Sorry dude, but I don't think it would work.
( ) This is a stupid idea, and you're a stupid person for suggesting it.
( ) Nice try, assh0le! I'm going to find out where you live and burn your
house down!
There are shills on slashdot. Apparently, I'm one of them.
This strikes me as the ultimate in temporary solutions. If spam senders *tend* to use only the primary MX record, and people start fighting spam by listing bad primaries, won't the spam senders simply start using secondaries? It almost seems the only way that this approach might be valuable, is if it weren't publicized and posted on /., and one kept it to oneself :)
Love many, trust a few, do harm to none.
This is not a long term solution.
1) It's bad netiquette, and a lot of people don't like that, including myself and I'm sure many other administrators.
2) It's an artificial "defense" that is easily circumvented because the rule is obvious. It's security through obscurity with the added suck that there is no obscurity.
3) It's solving a symptom and not any of the actual problems (e.g. hosts being compromised to send spam).
Thanks, but I'll pass.
"Nature doesn't care how smart you are. You can still be wrong." - Richard Feynman
We get stuff directed at our secondary all the time, despite having a highly available primary. Why? Our secondary is listed at another domain - they do our backup in the case of disaster. I can only assume that spammers hit it thinking that its a 'back door' into the network, perhaps we don't have the same rigorous anti-spam measures there.
Dumb idea. You're better sending all your domain mail to gmail, using their spam filtering, and then pulling it from there.
I want to delete my account but Slashdot doesn't allow it.
Most spam bots already send to the *lowest* priority MX (ie. the highest number), and work their way backwards, because it's common for the backup MX'es to have lower anti-spam rules.
However, this idea would have been *great* six years ago. Once the developer invents a time machine, he's got the spam problem licked for at least a week!
Based on watching a few corporate spam sites and even stuff which reaches my private, never-posted addresses, *much* of the spam could be eliminated by moving non-Windows clients. I'm not just talking about zombies. Some of the spam I see hits lists of addresses which are valid and include very difficult to guess addresses inside the company. Once somebody inside your company, or a buddy of yours is rooted, your previously private address is out there; I've never had this happen via any route but a Windows user. Of course, people who CC: everybody they know with idiotic crap instead of BCC: make this problem much worse.
Oh, and please stop with the lame form letter responses to these articles. It was cute once, long ago. I know at least five people will have posted them by now. Damn spammers.
Spammers will often try secondary (and lower) MX's because there's a good chance that the anti-spam AND ANTI-VIRUS systems on those machines are weaker (read "outdated") than on the primary MX.
The more machines you have to maintain, the more likely you are to focus your efforts on the most critical ones and just let the other slide. Spammers are happy to exploit this.
Gmail's filtering is, well, badass. I'd think a large number of companies would be willing to pay them to handle email for their domains and forward to a company mail server which only accepts messages via gmail. You'd get a very nice web interface, but could still have the speed and power of a local POP/IMAP server. And virtually no spam. That would be worth a few bucks a month per account for a lot of people. Me, I'd be a little creeped out by them having that much access to my personal emails. Which is why I only use gmail for stuff that I don't want lost in a spam filter, like job searching, financial transactions, attorneys, my friends traveling in the Middle East, etc. But nothing personal!
Spam is NOT free speech. You cant come into my home screaming penis ads at me without getting your ass kicked, so why should you be able to do it into my mail server?
Sorry, this isn't going to work. It won't even help a little bit. As a long-time email administrator and the author of an email server I can tell you, with absolute certainty, that spammers ignore the priority of your MX records. In fact, they exploit multiple MX's much of the time, by sending spam to your secondary server(s) even if the primary one is up. In addition to extra target capacity, they often manage to take advantage of badly configured secondaries that might not have spam filtering that's as good as the primary, and in many cases the primary has its secondaries whitelisted to make sure no mail gets accidentally dropped.
Tired of FB/Google censorship? Visit UNCENSORED!
How comes everyone tries to fight spam by breaking infrastructure? Wikipedia neuters links, email server admins delay mails (graylisting) or even reject connections (unlisting), users turn off Flash and Javascript to avoid ads. IMHO, if we have to break our own toys to keep the spammers from playing with them, we're heading for dull times.
You need not open your mail, esp. when the subject line is something that you aren't interested;
You need not open your mail to have your resources (bandwidth, disk space, processing power) consumed by spam. I work at a major telecom company running the edge mail servers, along with another full time engineer. Of the 12 million emails we get a day, about 100,000 are legitimate mail. The rest is just spam, and it uses up the bandwidth that could've been resold to customers, it uses up the disk space on the expensive mail servers we bought a few months ago, hell it forced us to buy those expensive new servers in the first place. I figure, just in the extra salary (if not for the spam one guy would be enough to handle the load), having to upgrade perfectly adequate five year old servers, and buying licenses for anti-spam products at four different levels of mail delivery throughout the enterprise just to keep our users from being deluged with useless garbage, the company has spent about $200,000 last year, and will spend about the same amount this year. All because a bunch of asshats want to force our employees to read their idiot advertising, using our network resources to push their message.
That's not free speech, that's theft. And that's never been legal.
God invented whiskey so the Irish would not rule the world.
I for one welcome our soon-to-be-RFC-compliant spammer overlords. I mean, we want standards compliance, right? Right??
This post expresses my opinion, not that of my employer. And yes, IAAL.
I have read some truly terrible ideas on this website. (Usually followed by a chorus of inexperienced idiots blindly saying how great they are, while all the skilled and experienced people rolled their eyes.)
This is one of the worst ideas I have ever read. Intentionally introducing a large and unpredictable delay into the receipt of all e-mail.
What's next, a recommendation to cut down on telemarketing by setting your PBX to automatically disconnect 50% of all incoming calls?
Right, because it would be real tough to get the users ISP-provided SMTP relay from their Outlook configuration and just spam via. that instead. The spammers would never figure that one out.
Oh and I have the RIAA and MPAA on line 1. They say that if the ISPs are going to be the internet traffic police, they want to talk to them about this BitTorrent thing..
The first time I ever saw one of those "forms", I thought it was interesting.
The second time, I thought it was "ho-hum".
After hundreds, maybe even thousands, they are just plain lame.
The only good thing about them is that you instantly know that you can skip over them and not miss anything at all.
Actually, as long as it is correctly filled in, I find that form consistently insightful.
The reason is that a lot of people preach some new approach to fighting spam, and in reality there are a finite set of reasons which defeat every single one of these ideas to date. When someone comes up with an approach that passes this form, then we'll have something to talk about. If it can't pass this form, then further discussion isn't really merited since it's not even novel enough to get past the standard set of objections that have so far been raised against and successfully predicted the downfall of every failed anti-spam solution to date.
Ideas that can't pass the form are not worth more effort to respond to than putting an X at the appropriate spots on the form.
Slay a dragon... over lunch!
For now I'll stick with SPF and old fashioned spamassassin (milter).
And whats with the anti SPF sentiment? Its not like we've got a lot of more effective alternatives on the market and the only real argument I read is the rejection of real email, when softfail pretty much takes care of that (then leaving it to spamassassin to decide if the mail is legit).
We send an receive a good deal of email and I certainly wish SPF was more common. I'm tired of forged bounces and the *slew* of undeliverable responses 'dumb' servers return to our system every day.
Yet instead of taking any real action we bicker while spammers laugh all the way to the bank. Their is no magic bullet, but from my POV SPF is the closest thing yet (unless my DNS gets hi-jacked, but then I'm fucked anyway).
Quack, quack.
The joke is that the 'free speech' bus left years ago.
We don't need to outlaw Unsolicited Commercial Email, or Unsolicited Bulk Email, or do anything to make spam illegal. ALL spam is already illegal, because ALL spam is being sent by illegally hijackjed Windows machines.
Note when I say 'All spam', I actually mean 'All spam still happening on the internet'. There are no 'legitimate' spammers anymore, because they were almost all dropped from the internet five years ago, and the few remaining ones find themselves utterly blocked by everyone in existence. All spam that is actually ending up mailboxes is being sent illegally.
We don't need to fucking argue over what 'rights' people have, taking control of someone else's computer and using it to do anything is a 100% flat-out felony.
If corporations are people, aren't stockholders guilty of slavery?