What this Means for Email Marketers
If you are a sender, your IP/domain may show as blacklisted by the above blacklist. If a domain references blacklisting by AHBL as reason for rejecting your messages, feel free to let them know that they need to update their blacklist query.
If you are operating an inbound mail server that checks against dnsbl.ahbl.org, ircbl.ahbl.org, or rhsbl.ahbl.org, you should stop doing so as soon as possilbe, as you may be seeing false positive listings.
The unfortunate truth is that AHBL could have configured their system to return a “no” response to all queries upon sunsetting the service. This would mean that no IP or domain would show as being blacklisted by them, rather than the current state where they have effectively blacklisted the entire internet. There exist arguments for either side, but I lean toward the latter, which would keep from inconveniencing many many people who may be innocently sending mail that may be rejected due to a false positive blacklist result by AHBL.