Tagdnsbl

List the world!

We often say that a blacklist has “listed the world” when it shuts down ungracefully. What exactly does that mean, and why does it happen? Blacklists are queried by sending a DNS lookup for an A record, just the same as you’d find the address of a domain for opening a webpage there. The IP address or domain name that’s being queried is encoded in the hostname that’s...

SpamCannibal is dead

The SpamCannibal blacklist – one that didn’t affect your email too much but which would panic users who found it on one of the “check all the blacklists!” websites – has gone away. It was silently abandoned by the operator at some point in the past year and the domain registration has finally expired. It’s been picked up by domain squatters who, as usual, put a...

Help! We're on Spamhaus' list

While trying to figure out what to write today, I checked Facebook. Where I saw a post on the Women of Email group asking for help with a Spamhaus listing. I answered the question. Then realized that was probably useable on the blog. So it’s an impromptu Ask Laura question. We’re listed on Spamhaus’ list, any advice on how to get off? Our email provider has a plan, just looking...

News in the email space

Various things happening in the email space recently that are worth mentioning but don’t have enough to justify a whole blog post. Verizon announced a new umbrella company for the AOL and Yahoo media properties, including things like Engadget, Huffington Post. Based on the various press articles I’ve seen this doesn’t appear to affect the email handling for either set of domains...

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...

DNSBLs, wildcards and domain expiration

Last week the megarbl.net domain name expired. Normally this would have no affect on anyone, but their domain registrar put in a wildcard DNS entry. Because of how DNSBLs work, this had the effect of causing every IP to be listed on the blocklist. The domain is now active and the listings due to the DNS wildcard are removed. How does a domain expiration lead to a DNSBL listing the whole internet...

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...

Fake DNSBLs

Spamhaus recently announced a few years ago that they have discovered a company that is pirating various blocklists, relabeling them and selling access to them. Not only is the company distributing the zones, they’re also running a “pay to delist” scheme whereby senders are told if they pay money, they’ll be removed from the lists. The fake company does remove the listing...

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