Spamhaus Speaks

There’s been a lot of discussion about Spamhaus, spam traps, and blocking. Today, Spamhaus rep Denny Watson posted on the Spamhaus blog about some of the recent large retailer listings. He provides us with some very useful information about how Spamhaus works, and gives 3 case studies of recent listings specifically for transactional messages to traps.
The whole thing is well worth a read, and I strongly encourage you to check out the whole thing.
There are a couple things mentioned in the blog that I think deserve some special attention, though.
Not all spam traps actually accept mail. In fact, in all of the 3 case studies, mail was rejected during the SMTP transaction. This did not stop the senders from continuing to attempt to mail to that address, though. I’ve heard over and over again from senders that the “problem” is that spamtrap addresses actually accept mail. If they would just bounce the messages then there would be no problem. This is clearly untrue when we actually look at the data. All of the companies mentioned are large brick and mortar retailers in the Fortune 200. These are not small or dumb outfits. Still, they have massive problems in their mail programs that mean they continue to send to addresses that bounce and have always bounced.
Listings require multiple hits and ongoing evidence of problems. None of the retailers mentioned in the case studies had a single trap hit. No, they had ongoing and repeated trap hits even after mail was rejected. Another thing senders tell me is that it’s unfair that they’re listed because of “one mistake” or “one trap hit.” The reality is a little different, though. These retailers are listed because they have horrible data hygiene and continually mail to addresses that simply don’t exist. If these retailers were to do one-and-out or even three-and-out then they wouldn’t be listed on the SBL. Denny even says that in the blog post.

We do not list IPs because of one-off transactional emails sent to a few spamtraps. If the email stream is persistent over time, especially high volume, and drifts outside the relationship of individual transactions, we may find these messages a problem.

Spamtraps are not just typo domains. In the 3rd case study, Spamhaus mentions that the domain in question expired in 2010, and was picked up by Spamhaus. This is not that uncommon an occurrence. Domains expire out of registration all the time, and sometimes they’re registered by new owners. Even if those new owners start using the same email addresses that the old owners did, there is no permission. If a domain goes away for a year or more and then comes back, it is folly to believe this is the same as it was.
Spamhaus isn’t out to catch senders who make the occasional mistake. Spamhaus has a policy of keeping traps dormant for a period of time (at least 6 months, but more often a year) before accepting any mail there. Spamhaus isn’t listing for a single trap hit. They’re really only listing senders with continual and ongoing problems.
There is so much myth and legend about what Spamhaus does and doesn’t do. And while I, and others in the delivery space, are more than comfortable acting as Spamhaus mouthpieces (sometimes after clarifying points with them, sometimes just acting on our own), it’s nice to have information directly from them.
Based on discussions I’ve seen in lots of other places, this isn’t going to be the last post I write on Spamhaus this month (possibly even this week, if things keep going the way they are). But I think it’s important to highlight their own words and their own data whenever possible.

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Spamhaus dDOS

I got mail late last night from one of the Spamhaus peeps telling me that they were under a distributed Denial of Service (dDOS) attack. This is affecting email. Incoming email is delayed and they’re having difficulty sending outgoing email. This is affecting their responses to delisting queries.
They are working on mitigation and hopefully will be fully up and running soon.
Updates when I get them.
Update (8/29/2012): mail to Spamhaus should be back.

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A Disturbing Trend

Over the last year or so we’ve been hearing some concerns about some of the blacklisting policies and decisions at Trend Micro / MAPS.
One common thread is that the ESP customers being listed aren’t the sort of sender who you’d expect to be a significant source of abuse. Real companies, gathering addresses from signup forms on their website. Not spammers who buy lists, or who harvest addresses, or who are generating high levels of complaints – rather legitimate senders who are, at worst, being a bit sloppy with their data management. When Trend blacklist an IP address due to a spamtrap hit from one of these customers the actions they are demanding before delisting seem out of proportion to the actual level of abuse seen – often requiring that the ESP terminate the customer or have the customer reconfirm the entire list.
“Reconfirming” means sending an opt-in challenge to every existing subscriber, and dropping any subscriber who doesn’t click on the confirmation link. It’s a very blunt tool. It will annoy the existing recipients and will usually lead to a lot of otherwise happy, engaged subscribers being removed from the mailing list. While reconfirmation can be a useful tool in cleaning up senders who have serious data integrity problems, it’s an overreaction in the case of a sender who doesn’t have any serious problems. “Proportionate punishment” issues aside, it often won’t do anything to improve the state of the email ecosystem. Rather than staying with their current ESP and doing some data hygiene work to fix their real problems, if any, they’re more likely to just move elsewhere. The ESP loses a customer, the sender keeps sending the same email.
If this were all that was going on, it would just mean that the MAPS blacklists are likely to block mail from senders who are sending mostly wanted email.
It’s worse than that, though.
The other thread is that we’re being told that Trend/MAPS are blocking IP addresses that only send confirmed, closed-loop opt-in email, due to spamtrap hits – and they’re not doing so accidentally, as they’re not removing those listings when told that those addresses only emit COI email. That’s something it’s hard to believe a serious blacklist would do, so we decided to dig down and look at what’s going on.
Trend/MAPS have registered upwards of 5,000 domains for use as spamtraps. Some of them are the sort of “fake” domain that people enter into a web form when they want a fake email address (“fakeaddressforyourlist.com”, “nonofyourbussiness.com”, “noneatall.com”). Some of them are the sort of domains that people will accidentally typo when entering an email address (“netvigattor.com”, “lettterbox.com”, “ahoo.es”). Some of them look like they were created automatically by flaky software or were taken from people obfuscating their email addresses to avoid spam (“notmenetvigator.com”, “nofuckinspamhotmail.com”, “nospamsprintnet.com”). And some are real domains that were used for real websites and email in the past, then acquired by Trend/MAPS (“networkembroidery.com”, “omeganetworking.com”, “sheratonforms.com”). And some are just inscrutable (“5b727e6575b89c827e8c9756076e9163.com” – it’s probably an MD5 hash of something, and is exactly the sort of domain you’d use when you wanted to be able to prove ownership after the fact, by knowing what it’s an MD5 hash of).
Some of these are good traps for detecting mail sent to old lists, but many of them (typos, fake addresses) are good traps for detecting mail sent to email addresses entered into web forms – in other words, for the sort of mail typically sent by opt-in mailers.
How are they listing sources of pure COI email, though? That’s simple – Trend/MAPS are taking email sent to the trap domains they own, then they’re clicking on the confirmation links in the email.
Yes. Really.
So if someone typos their email address in your signup form (“steve@netvigattor.com” instead of “steve@netvigator.com”) you’ll send a confirmation email to that address. Trend/MAPS will get that misdirected email, and may click on the confirmation link, and then you’ll “know” that it’s a legitimate, confirmed signup – because Trend/MAPS did confirm they wanted the email. Then at some later date, you’ll end up being blacklisted for sending that 100% COI email to a “MAPS spamtrap”. Then Trend/MAPS require you to reconfirm your entire list to get removed from their blacklist – despite the fact that it’s already COI email, and risking that Trend/MAPS may click on the confirmation links in that reconfirmation run, and blacklist you again based on the same “spamtrap hit” in the future.

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What causes Spamhaus CSS listings

Today’s Wednesday Question comes from Zaib F.

What causes the Spamhaus CSS listing in your experience other than Sender using multiple sets of IPs, to look as if they are a valid sender. Do you think a Spamtrap plays a role?

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