What is nsZones SURBL/Spam URI Realtime Block List (UBL)?
The nsZones SURBL/Spam URI Realtime Block List (UBL) is a type of blacklist, specifically a SURBL (Spam URI Realtime Block List). SURBLs are curated lists of domain names that have been observed within the content of unsolicited or spam emails.
Unlike a traditional IP-based blocklist, this list focuses on Uniform Resource Identifiers (URIs), which are essentially the domain names found in an email's body. For example, if the domain 'spamwebsite.com' is included in a marketing email, and that domain is on the ubl.nszones.com blacklist, receiving mail servers that use this list may filter the message as spam.
Technically, mail servers use the DNS system to check if a domain is listed. A DNS query for 'spamwebsite.com.ubl.nszones.com' will return a specific IP address, such as 127.0.0.4, if the domain is on the blocklist. This response signals to the mail server that a blacklisted domain was found.
Who runs nsZones SURBL/Spam URI Realtime Block List (UBL)?
The nsZones SURBL/Spam URI Realtime Block List (UBL) is operated by nsZones. The organization runs a system that identifies spam sources using DNS-based lists (also known as DNSBLs or RBLs). This allows email server administrators to check if an incoming email connection or a domain within a message is associated with known spam activity.
nsZones operates with the philosophy that its lists are defensive tools intended to help email receivers filter unwanted mail at their discretion. The organization maintains several different types of lists, including IP-based blacklists and domain-based blocklists (SURBLs).
In addition to its domain-based UBL, nsZones runs the following lists:
- bl.nszones.com: A combined zone that includes entries from other nsZones lists.
- sbl.nszones.com: Lists IP addresses of open relays, compromised PCs, and known spam sources.
- dyn.nszones.com: Contains dynamic IP address ranges from providers like ADSL and cable networks.
The service is supported in part by a network of public mirrors, which allows volunteers to host copies of the nsZones blacklists to help distribute the DNS query load.
How do I get removed and delisted from nsZones SURBL/Spam URI Realtime Block List (UBL)?
Before requesting removal from any blocklist (or blacklist), you must first identify and resolve the underlying issue that led to the listing. This might involve cleaning a hacked website, securing a compromised email account, or fixing a misconfiguration. If the core problem is not addressed, your domain will likely be listed again.
nsZones provides two options for delisting from the nsZones SURBL/Spam URI Realtime Block List (UBL):
- Automatic Expiration: A listing will be removed automatically and for free, but only after five years have passed since the last abusive activity was detected from the domain.
- Express Delisting: You can pay a fee of 7.95 EUR for an expedited manual removal. According to nsZones, this paid delisting includes a guarantee that the domain will not be re-listed for the next 24 months.
What's the impact of being listed on nsZones SURBL/Spam URI Realtime Block List (UBL)?
The overall impact of a listing on the nsZones SURBL/Spam URI Realtime Block List (UBL) is considered low. It is not widely adopted by major mailbox providers like Gmail, Microsoft Outlook, or Yahoo.
Despite its low impact score, a listing can still cause deliverability issues. Some corporate mail servers, smaller internet service providers, and spam filtering appliances may use this blocklist. Since it is a SURBL (a domain-based blacklist), the negative effect is tied to the content of your emails. Any message containing a link to a listed domain may be blocked or filtered to the spam folder, even if the sending IP address has a good reputation.
Spamhaus
0Spam
Cisco
NoSolicitado
URIBL
abuse.ro
ALPHANET
Anonmails
Ascams
BLOCKEDSERVERS
Calivent Networks
EFnet
JustSpam
Kempt.net
NordSpam
RV-SOFT Technology
Scientific Spam
Spamikaze
SpamRATS
SPFBL
Suomispam
System 5 Hosting
Team Cymru
Validity
www.blocklist.de Fail2Ban-Reporting Service
ZapBL
2stepback.dk
Fayntic Services
ORB UK
technoirc.org
TechTheft
