I'll leave a detailed response to those more familiar with URIDNSBL internals, but the goal is to remove all but the base domain before comparing it to an SURBL. So I'm hoping any deliberately randomized characters and any other extra stuff is discarded before RBL comparison. Only the basic domain should be checked against the SURBL.
Currently, SURBL relies on get_uri_list the grab the list of domains, some uri's may not be appropiate as the basis for which to grab domains for. If that list could be cut down, then the pool from which the random selection is made could be more interesting
e.g, I could write a message with maybe 25-30 cid:.* url's and one real-spamvertised url'. The probability of URIDNSBL.pm to get the spamvertised url will be higher if the noise from the cid:.* url or other non-interesting url's could be removed
PS, Does this list need to have the listname prefixed to the subject line, it wastes a lot of space. I am sure there are other headers one can filter by
Regards, Yusuf