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Unsubscribe Blacklist (UBL) Resources

What is the UBL?

The Unsubscribe Blacklist (UBL) is a real-time blacklist of IP addresses which are sending email to names harvested from suppression files.

Statistics

New IPs in the last 48 hours 29,618

IPs Removed in the last 48 hours 45,176

Delist Requests in the last 48 hours 453

Total IPs Listed 773,197

About the UBL

Utilizing the world’s largest unsubscribe intelligence database, LashBack’s Unsubscribe Blacklist (UBL) empowers your organization to identify and block the very worst unsubscribe abusers; those that send email to addresses which have been harvested from suppression lists.

LashBack has been monitoring sender unsubscribe compliance since 2003. During this period, LashBack has compiled sender unsubscribe compliance failure in four primary categories:

1. Which senders fail to provide a working unsubscribe mechanism
2. Which senders do not honor unsubscribe requests within 10 business days
3. Which senders allow consumers unsubscribe request to be abused (i.e., shared with other parties to send more spam)
4. Which senders are taking suppression lists from other organizations and sending email to these lists

LashBack’s UBL only lists the IP addresses of senders who are using email addresses harvested from suppression lists (point 4). If you would like additional “premium” reputation data contact a LashBack representative directly.

This free service is intended to provide all receivers and reputation providers a baseline of data to help block the sender’s with the worst reputations. All IP addresses listed on in our service are being continually monitored and the list is updated hourly.

Web Lookup

To perform ad-hoc lookups or to delist an IP for the first time, please visit the UBL Lookup and delist page.

XML Download

If you wish to download an XML copy of the blacklist, this file is available at the XML UBL download link. This XML file is updated hourly with the latest blacklist data.

Text Download

If you wish to download a text copy of the blacklist, this file is available at the text UBL download link. This text file is updated hourly with the latest blacklist data.

RBLDSND Format Download

If you wish to download a copy of the blacklist in RBLDNSD format, this file is available here. This file is updated hourly with the latest blacklist data.

RSYNC Access

All downloadable files are available via RSYNC at:
rsync://rsync.unsubscore.com/LBBL/blacklist.xml (XML)
rsync://rsync.unsubscore.com/LBBL/blacklist.txt (TEXT)
rsync://rsync.unsubscore.com/LBBL/ubl_rbldns.txt (RBLDNSD)

DNS Lookups

This service is a list of hostnames in the ubl.unsubscore.com zone. These hostnames may appear to be real IP Addresses. However, they are hosts in the ubl.unsubscore.com DNS zone.

In order to check whether an IP is listed in the UBL, you can perform a DNS query using the IP address of the sender. However, you must reverse the IP address in order to perform the query. For example, if you wish to check whether 192.168.1.100 is listed in the UBL, you would perform a DNS lookup on 100.1.168.192.ubl.unsubscore.com. If one of the DNS return codes listed below is returned, then the IP is listed in the UBL.

UBL Return Codes

Currently the LashBack UBL supports the following return codes. Please note that LashBack will likely continue to add additional return codes over time.

127.0.0.2 - This return code indicates that the IP address has sent to email LashBack unsubscribe probes. These senders are taking email addresses from unsubscribe requests and spamming them.

Zone Transfers

Currently the UBL allows anonymous zone transfers of ubl.unsubscore.com.

Mail Server Configuration

The LashBack UBL can be used for any mail server supporting connection level blacklists. The blacklist server should be set to ubl.unsubscore.com.

Data Use Restrictions

The UBL database is provided free for both commercial and non-commercial use.

DISCLAIMER OF WARRANTIES AND LIABILITY

All data is provided for your personal information only, and not intended for legal purposes. LashBack LLC is not liable for any errors in the data, or for any actions taken in reliance thereon.

LASHBACK LLC MAKES NO WARRANTY, EXPRESSED OR IMPLIED, AS TO THE RESULTS TO BE OBTAINED BY ANY USER OR OTHERS FROM THE USE OF THE INFORMATION PROVIDED HEREUNDER. LASHBACK MAKES NO EXPRESS OR IMPLIED WARRANTIES OF FITNESS OF THE INFORMATION FOR A PARTICULAR PURPOSE OR USE.

The information contained in LashBack databases has been developed by LashBack and are considered by LashBack to be reliable. However, the accuracy and completeness thereof are not guaranteed and LashBack and its data suppliers shall have no liability for errors or omissions regardless of the cause or source of such error or omission.

LASHBACK LLC DOES NOT HAVE ANY LIABILITY TO A USER OR TO OTHERS FOR ANY LOST PROFITS OR INDIRECT, SPECIAL, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES, EVEN IF ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES.

LashBack may change or discontinue the databases, or their availability to you, at any time without notice.