DNSBL Listing & Removal Policy

List Additions

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.

List Removals

ISP and Hosting Provider Expedited Removals:

Our normal quarantine period is 30 days from receipt of the last spam. We may be able to expedite removals under the following conditions:

The IP in question is not listed by other well-known block lists (Spamhaus, SORBS, AHBL, etc.) and;
The IP address has not been previously removed and then re-listed and;
The total volume of spam is relatively insignificant and;
The spam does not include phishing emails and;
We can reasonably verify that the requester is a responsible party for the provider.

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 cannot remove records with incorrect DNS settings. Both of the following are required:

Reverse DNS: The IP must resolve to a host and;
That host must resolve back to the same IP address.

Subject to DNS accuracy (see above), we will remove records from the spam list if we receive a request and have received no spam from the IP address for at least 30 days.

Errors to the dynamic list will be corrected promptly. We require that the IPA has a proper reverse pointer. Our minimum TTL requirement is 14,400 seconds. TTL = 86,400 seconds is recommended.

Most 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 without a non-standard reverse pointer (which Roadrunner will provide immediately upon request).

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.

Records Retention

We will retain original mail logs for a period of two years. We will maintain two years of DNSBL adds and rejections in a MySQL database. We began retaining records on January 5, 2005.