What is blacklist.zap?

Here's a blast from the past: Remember blacklist.zap?

There were various "blacklist.zap" lists and they were all indicative of blocking when sending to mailboxes hosted behind "FrontBridge" anti-spam and security protection:

• The list 85.blacklist.zap specifically referred to FrontBridge's use of the Composite Blocking List (CBL). If you were blocked by 85.blacklist.zap, it meant that your sending IP address was listed on the CBL.
• The list 86.blacklist.zap specifically referred to FrontBridge's use of the Spamhaus Block List (SBL). If you were blocked by 86.blacklist.zap, it meant that your sending IP address was listed on the SBL.
• The list 87.blacklist.zap specifically referred to FrontBridge's use of the Spamhaus Exploits Block List (SBL). If you were blocked by 87.blacklist.zap, it meant that your sending IP address was listed on the XBL.
• The list 88.blacklist.zap specifically referred to FrontBridge's own internally-generated blacklist of sending IP addresses noted to be spammy, usually based on a high percentage of mail from that IP address being denoted as spammy.

FrontBridge was later acquired by Microsoft and I think it's been a long time since anybody has seen blacklist.zap blocking in a bounce message, but I thought it would be good to keep a record of this for posterity's sake.

Status of dnsbl.burnt-tech.com: DEAD

Uh-oh! On or about September 19th, the domain burnt-tech.com seems to have expired. Now when you visit the website, you are informed that the domain is for sale. Also, you'll now find a wildcard A record in DNS, meaning that any lookup of any host name in DNS under burnt-tech.com will result in a positive response being returned.

The net result here is that due to the domain now having a wildcard A record, any users of the Burnt Tech DNSBL now find that they are blocking all inbound mail. If you were using the dnsbl.burnt-tech.com blocking list to filter inbound spam, you'll need to remove it from your mail server or spam filter configuration immediately, as it is going to impede your ability to receive any mail.

Reviewing Internet Archive versions of the Burnt Tech DNSBL website, it appears that the list has been in action since at least 2006. From a 2015 archived copy of the website: "The Block List runs entirely automated and designed to avoid listings of spamtrap hits due to bounces of forged spam, virus bounces, and "real" mail servers emitting the occasional spam. It tries very hard to avoid listing legitimate mail sources. It does not attempt to list every possible spam source."

No other information was available regarding ownership, listing criteria or history of this DNSBL.

(H/T: Matthew Vernhout)