The Schulte DNS Based Spam Block List (RBL) is a personally managed IP blacklist created by Christopher Schulte to block email from IP addresses that have sent spam to his servers, and it notably has no official delisting process.
The Schulte DNS Based Spam Block List (RBL) is a publicly available IP-based blocklist created and maintained by Christopher Schulte. Originally, it was a personal project to manage unwanted email across multiple SMTP servers. The operator decided to publish the list of IP addresses he did not want to receive mail from via DNS, making it easy to use across his infrastructure without manual updates.
The listing policy is based on the operator's personal criteria. IP addresses are added when they are identified as sources of spam. The blacklist also includes broader ranges; entire /24 or /16 CIDR blocks are added if they are the source of repeated spam and the operator does not anticipate receiving any legitimate email from them. This is a DNSBL (Domain Name System Blocklist) and can be queried at the zone rbl.schulte.org.
This RBL is just one component of a much larger and more comprehensive email filtering strategy. The full solution includes a variety of methods:
The Schulte DNS Based Spam Block List (RBL) is run by Christopher Schulte. He is a technology professional with over 20 years of experience in fields such as Networking, Digital Forensics, Cyber Security, and Incident Response. He holds degrees in Computer Forensics and Criminal Justice, in addition to various industry certifications.
There is no delisting process for the Schulte DNS Based Spam Block List (RBL). The operator's official policy states that if you are blocked, you have no choice but to resend your email from a different host or IP address that is not on the blacklist. This blocklist is a personal list, and removal requests are not accepted.
While there is no way to request delisting, the operator provides an email, postmaster@schulte.org, for general communication about the list.
The impact of being listed on the Schulte DNS Based Spam Block List (RBL) is generally low. This is not a blacklist used by major mailbox providers like Gmail, Microsoft, or Yahoo. It is a personal list that is made public for others to use if they choose.
If your emails are being blocked by this specific blacklist, it is for one of two reasons: you are either trying to send an email to a server directly managed by Christopher Schulte, or you are sending to an organization that has voluntarily decided to use this RBL as part of its filtering system. Therefore, the impact of this blocklist is limited to a small number of mail servers that have explicitly configured it.
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