The SORBS (Spam and Open Relay Blocking System), owned and operated by Proofpoint, Inc., provides free access to its DNS-based Block List (DNSBL) to effectively block email from more than 12 million host servers known to disseminate spam, phishing attacks, and other forms of malicious email. The list typically includes email servers suspected of sending or relaying spam, servers that have been hacked and hijacked, and those with Trojan infestations. In an attempt to provide preemptive protection, SORBS also lists servers with dynamically allocated IP addresses.
Sorbs Duhl Reports Subnets
Subnet-based Blacklists are used to reject email from entire ranges of IP Addresses, i.e. providers that are hosting companies sending spam, as well as single IP Addresses that may fall in that range of IP Address.
Sorbs Duhl Reports Dynamic Ip Addresses
Dynamic-based Blacklists will list many DHCP ranges of IP Addresses from Internet Service Providers. You could be listed if your IP Address was previously dynamically assigned, or if your ISP gave you a static assignment and did not assign a distinguished PTR-Record, aka a "Reverse DNS Entry."
Sorbs Duhl Requires A Manual Delisting Request
This blacklist does support a manual request to remove or delist your IP Address from their database. Please note that removal requests that are submitted without addressing the core problem will likely result in your IP Address or Domain being relisted in that database, which can cause subsequent problems and extended listing periods without release.
DMARC is the key to improving Email Deliverability!
Email is the key to your customer communication strategy. But, what is your email reputation?
Setting up and managing your DMARC configuration is the key to getting insight into your email delivery. MxToolbox is the key to understanding DMARC.
MxToolbox Delivery Center gives you:
- Who is sending phishing email purporting to be from your domain
- What is the reputation of your domains and delegated IPs
- Where other senders are and What their reputations are
- How your SPF, DKIM and DMARC setup is performing
- What on-going maintenance you need to maintain and improve your email deliverability
Learn More