We maintain a number of spam traps across a number of domains. Email sent to a spam trap is automatically added to the spam list. Email that is not directed to a spam trap is analyzed for a spam “signature” and added as well. The process is completely automated; Updates are in real time. It takes from one to 60 seconds for the listing to show up in a multi-RBL query.
In addition to UCE and UBE, we consider backscatter and c/r challenges to be spam (see our definition of spam).
As IP addresses are added they are tested to determine if they are part of a residential or dynamic range. Dynamic IPAs are added to the dynamic list in blocks of /24. Therefore, the actual dynamic spam client is duplicated in the spam list. We also use other, publicly available, data to maintain the dynamic ranges list. At this time, IPAs that do not resolve to a host (“unknown”) are not added to the dynamic list. That may change in the near future.
Manual additions to the list are piped to the daemon through a script. This allows them to be examined for DHCP and a record of the addition is printed to the mail log.
Requests to remove IPAs from the lists are done through a DNSBL removal form. We make every effort to provide less than a four hour turnaround. All removal requests are confirmed or denied by email.
Please note that we do not white list.
We will remove records from the spam list if we receive a request and if we have received no spam from the IPA for at least 30 days. We do not expire records automatically. We will not remove an IP address that does not have a reverse pointer.
Errors to the dynamic list will be corrected promptly. We require that the IPA has a proper reverse pointer. Some providers mix static and dynamic assignments in the same ranges. In that case, the /24 is considered to be dynamic. Sorry but ISPs should provide distinct allocations. Furthermore, static hosts should have TTL => 86,400 seconds.
Many dynamic list problems are the result of generic reverse pointers. We will remove listings that are clearly static. RoadRunner Business Customers: Please note that, until further notice, we will be adding generic “biz.rr.com” to the dynamic list. These listing cannot be removed.
We strongly recommend the use of unique rDNS (“mail.domain.tld”). Filtering on generic pointers is becoming more prevalent because they do not provide accountability to the responsible domain. Abuse must be reported to the ISP rather than the domain holder.