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 over 12 million host servers known to disseminate spam, phishing attacks, and other forms of malicious email. This blacklist typically includes email servers that are suspected of sending or relaying spam, servers that have been hacked and hijacked, and servers with Trojan infestations. Additionally, SORBS also lists servers with dynamically allocated IP addresses.
Sorbs Spam 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 Spam Reports Sources Of Spam
Spam-based Blacklists are those that will list either single IP Addresses or entire ranges that have actually received Spam, i.e. Unsolicited Bulk Email (UBE) in their Spamtraps from an IP-Address. This could be a result of a compromised email account, an Open Relay, or simply sending mass emails / marketing and not following best practices according to the "CAN-SPAM Act of 2003" (ref: https://en.wikipedia.org/wiki/CAN-SPAM_Act_of_2003)
Sorbs Spam Reports Virus Infected Sources
Virus-based Blacklists are those that will list single IP Addresses (or hostnames) of email servers that have sent Spam traffic that is generated by some form of a Virus, Malware, Trojan, or "botnet" infection in a network. This is often a result of a user visiting a webpage that houses an infection and downloads malware on a PC which then creates a "mini SMTP" server used to hijack account information, and send bulk email to recipients in the Users' email address book. It can affect the actual machine housing the "Email server platform" or on a local PC which is allowed to connect to the Email Server IP Address on SMTP port 25.
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
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- 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
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