[SURBL-Discuss] RFC: SURBL software implemetation guidelines
Jeff Chan
jeffc at surbl.org
Tue Apr 13 17:13:54 CEST 2004
I'm adding a very brief section to the Quick Start of the SURBL
site:
> Implementation guidelines
> Here are some very brief instructions for folks writing
> software to use SURBL lists: You code should:
>
> 1. Extract URIs from message bodies
> 2. (Extraction of URIs from message bodies should ideally
> include full resolution of redirections into the final target
> domain name. This can be a non-trivial problem.)
>
> 3. Extract base (registrar) domains from those URIs
> 4. Not do name resolution on the domains
> 5. Look up the domain name in the SURBL by prepending it to
> the name of the SURBL, e.g., domainundertest.com.sc.surbl.org
> then doing Address record DNS resolution. A non-result
> indicates lack of inclusion in the list. A result of 127.0.0.2
> represents inclusion.
> 6. Handle numeric IPs in URIs similarly, but reverse the
> octet ordering before comparison against the RBL. This is
> standard practice for RBLs. For example, http://1.2.3.4/ is
> checked as 4.3.2.1.sc.surbl.org
>
> SURBL lists unusually have both names and numbers in the same
> list. For example, 2.0.0.127 and example.com and similar actual
> spam domains and addresses are both in all SURBL lists.
> Numbered addresses in SURBLs are to have occurred as numbers in spams.
Can anyone think of any additions, corrections, or suggestions
before I announce it more broadly?
Jeff C.
--
Jeff Chan
mailto:jeffc at surbl.org
http://www.jeffchan.com/
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