[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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