Sorbs DUHL Blacklist: What Is It and How To Remove Yourself From It?

The Warmup Inbox Team
The Warmup Inbox Team

What Is The Sorbs DUHL Blacklist?

The Sorbs DUHL is a blacklist that compiles a list of dial-ip ranges.  Sorbs DUHL stands for Dynamic User and Host List.  This is a relatively small blacklist because cable modems and DSL access has severely decreased the number of dial-up customers.  The blacklist looks for net blocks where the IP Address is dynamically assigned to users, regardless of the actual method it was connected with.  Having a dynamic assignment of IP Addresses creates a more difficult path for the Sorbs DUHL to identify spam.

How Does The Sorbs DUHL Blacklist Work?

The Sorbs DUHL lists dynamically assigned addresses from the spam messages that they receive.  The blacklist looks closely at the generic reverse DNS naming.

How Can I Remove Myself From The Sorbs DUHL Blacklist?

Sorbs DUHL entries never expire on their own.  The blacklist organization maintains a list of general rules when it comes to requesting to be delisted from their blacklist.  

Rule 1: The Regional Internet Registry Point of Contact is able to request removal of any listing from their space.  They can also request any listing to be added.  Note: the Regional Internet Registry cannot be dynamically assigned.  

Rule 2: Users can request for their IP Address to be removed if the reverse DNS naming is set to indicate static assignment.    

Rule 3: End users need to ask their Internet Service Providers to request the removal as they are not allowed to do it on their own.  

The Sorbs BUHL also allows requests on their site. You must register to make an account first.  The account is free and secure.  Be sure to confirm your account through your email.  Once your account is made, follow these steps:

  1. Log in to your new account
  2. Look up your hostname, your IP Address, or netblocks
  3. Create a support ticket to request removal

If eligible, you may be able to manage your own listings in the account and remove your IP Address manually.

How do I reduce my risk of getting onto the Sorbs DUHL Blacklist?

The best way to avoid getting listed on a blacklist is to engage in proper email practices such as...

  • Verify all email addresses before attempting outreach
  • Avoid sending unnecessary emails
  • Avoid the use of spam words within your email drafts
  • Keep your sending volume to a minimum (30-50 a day if your inbox has been warmed up with us for at least 30 days)

Blacklist: An online database that aggregates email addresses and domains that have been reported on multiple occasions to be sending out spam or malicious content to others on a large scale. These blacklists are used as a reference by mail servers in order to determine how safe it is to accept messages coming from unknown domains and addresses.

IP Address: Internet Protocol is a unique address that identifies a device on the internet or a local network.  IP is the set of rules governing the format of data sent via the internet or local network.



Blacklist