Innovative Logic Corp

Dial DNSBL

This is a private list of class C networks which we have assembled from our sendmail logs and dns queries over the last couple years. The basic premise of this list is that insecure hosts send email only when they have been compromised (hacked) and the owner is not aware of the situation or doesn't care.

It is our belief that the following is a list of some of the types of host names that fall into this category.

Names containing 'dsl', 'ppp', 'dial', 'modem', 'slip' or any other term which indicates that they are part of a collection of devices to which the general population connects.
Student dormitories, residences, labs, etc
Names using some or all of the IP they represent in their name, eg 123-123-123-123.myisp.net
Names that say "unassigned", "no-dns-yet", "unallocated" or otherwise indicate they are not supposed to be used.
Server farms, colocations, other collections of systems.
Others from time to time that are determined to fall into this general category.

There are currently 3470972 networks on this list.

You can find out if a network is on the list:

Getting off the list

Networks on this list are added after looking at all the hosts on the net. If the majority of the hosts are unnamed (and we got mail from one of them) or the hosts fit into the above categories, the net likely belongs there. We do make exceptions for specific hosts, but only rarely.

If we've made an error in assessing the network or there are extenuating circumstances we should consider, please send an email to us at dnsbl at invlogic.com and provide any necessary details (the Class C address, why it isn't appropriately listed). We will consider each request on a case by case basis and let you know the results. Again, the simplest method is publishing appropriate SPF records.

Getting through

The easiest means to get your message delivered is to publish SPF records for the domain. Our systems are configured to overlook the DNSBLs if the host is the legitimate sender for the given domain. Abuse of this (publishing +all records or sending spam via an authorized host) will result in the domain being added to our SPF DENY list, blocking it permanently.

As a last resort, we have created a special address that will allow you to send a message in spite of the above source and content filtering. By sending your message to:

bypass+<user>#<domain> at invlogic.com

where <user>#<domain> is the original address with the @ replaced by a #. For example:

bypass+access#linux.org at invlogic.com

Initially, someone here will review the message and pass it along to the recipient, eventually it may become more automatic. I would not recommend sending anything you're not comfortable having someone, besides the intended recipient, reading. This will only work for domains which we are locally responsible for, it isn't a generic forwarder. We reserve the right to permanently block anyone who abuses this feature.

For the complete story on how we handle email, click here.