Mark Andrews wrote:
Actually there can be false positive. ISP's who put address blocks into "dialup" blocks which have the qualification that the ISP is also supposed to only do it if they *don't* allow email from the block but the ISP's policy explicitly allows email to be sent.
Actually that's debatable - the SORBS DUHL is about IPs assigned to hosts/people/machines dynamically. We do not list addresses where the ISP have sent the list explictitly saying 'these are static hosts, but they are not allowed to send mail' - similarly we do list hosts in the DUHL where the ISP has said 'these are dynamic but we allow them to send mail' - it's about the people using the SORBS DUHL for their purposes, not for helping ISPs getting around the issue of whether to use SORBS as a replacement to port 25 blocking.
I wasn't thinking about SORBS. It was a general warning to only put blocks on lists where the usage matches the policy of the list. I was thinking about a Australian cable provider that doesn't do the right thing. I'm sure there will be other ISP's that also fail to check the list policy before nominating the address blocks for the lists. In reality there shouldn't be the need for dialup lists. Also most people don't really use the "dialup" lists correctly. They really should not be a absolute blocker. They should also turn off "dialup" pattern matching tests otherwise you are getting a double penalty for the same thing. Mark
Regards,
Mat -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: Mark_Andrews@isc.org