Terminology

There is a lot more to say here, and I’m working on a longer post to really talk about the underlying racism in tech and how we as an industry have failed.

In the deliverability space, specifically, the use of blacklist/whitelist is terminology rooted in racism (black is bad, white is good). Many DNSBLs use the block terminology and have done for a while. But there are still too many places that talk about blacklists and whitelists (including here even though we make an effort to not use those terms).

Better terminology is blocklist and safelist. I recommit to using blocklist as the right terminology and commit to using safelist moving forward.

It’s not enough. It’s not the only thing I am doing to support equality and fight racism. But I’m making the commitment here, publicly.

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Ongoing subscription attack

Brian Krebs posted a couple days ago about his experience with the subscription bomb over the weekend. He talks about just how bad it was over the weekend.

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Asking for help with a blocklist

There are often questions arising about how to go about getting off a particular blocklist. A few years ago I led the MAAWG effort to document what to if if you were On a Blocklist (pdf link). That document was aimed primarily at MAAWG members and deliverability experts with working knowledge of blocklists. I think, even now, it’s a good background on how to deal with a listing and mail being blocked.
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There have been discussions on multiple mailing lists over the last week or so about how to deal with listings at different blocklists. Many folks on these lists have extensive experience, so these are good places to ask. With that being said, a lot of the requests lack sufficient details to help.
So, if you’re ever on a blocklist and want some help from a mailing list about the problem, here’s a short guide for how to ask for help.

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How many blocklists do we need?

There’s been a discussion on the mailop list about the number of different blocklists out there. There are discussions about whether we need so many lists, and how difficult the different lists make it to run a small mail system (80K or so users). This discussion wandered around a little bit, but started me thinking about how we got to a place where there are hundreds of different blocklists, and why we need them.
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There is a lot of history of blocklists, and it’s long, complicated and involves many strong and passionate personalities. Some of that history is quite personal to me. Not only do I remember email before spam, I was one of MAPS’ first few employees, albeit not handling listings. I’ve talked with folks creating lists, I’ve argued with folks running lists. For a while I was the voice behind a blocklist’s phone number.
The need, desire and demand for different lists has come up over the years. The answer is pretty simple: there are many different types of abuse. One list cannot effectively address all abusive traffic nor have policies that minimize false positives.
Lists need different policies and different delisting criteria. The SBL lists based on volume of email to addresses that are known to have not opted in to receive mail. The PBL lists IPs where the IP owner (usually an ISP) says that the IPs are not supposed to be sending mail by their policy. URIBL and SURBL list domains, not IPs. Some lists have delisting requirements, some let listees remove themselves.
The policies of listing and delisting are not one size fits all, nor should they be.
There are two widely used lists that have significantly different delisting policies: the SBL and the CBL.
The SBL focuses on IP addresses they believe are under the control of or supporting the services of spammers. They measure this by primarily relying on spamtraps, but they also accept forwarded mail from some trusted individuals. Getting delisted from the SBL means explaining to Spamhaus what steps were taken to stop the spam from coming. It’s a manual process with humans in the loop and can require significant business process changes for listees. (We’ve helped dozens of companies resolve SBL listings over the years, contact us if you need help.)
On the other hand, the CBL is a mostly automated list. It lists ources of mail that aren’t real mail servers sending real mail, but are sending a lot of stuff. As they describe it:

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