Marvin Modules: DNSBL

The DNSBL stands for DNS-Based Black List. DNSBL's are servers that know which mail servers are insecure or known sources of spam. Since many people receive spam, any new spa, messages are reported to the DNSBL and the mail server it originated from is added to the blacklist. This encourages operators of these mail servers to fix their server or cancel the spammer's account as many ISP's will reject mail from them.

DNSBLs are maintained by administrators and/or employees associated with that server. They are constantly updating the records to keep up with the changing spam. When a new spam message is found, they add it to the database. If that same message is sent to a user and they have selected a DNSBL that had added it to their database, it would be rejected and would not arrive in the mailbox.

Here is what the interface looks like: