http://www.lashback.com/support/UnsubscribeBlacklistSupport.aspx

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.

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.