Re: Challenge-response mail filters considered harmful

[Alan Connor <alanconnor@earthlink.net>]

This procmail recipe would do the trick. No more spam on the list.

(there *might* be one or two, occassionally, but that password would
be promptly killed. )

Anyone subscribing to the list would have to validate their address
by answering a CR, which is *standard* pracice on the vast majority
of mailing lists.

They send you an email with your subscription info and ask you to
validate the address by returning it. To protect you from being
subscribed by someone else, is what they say.

This is a CR system......


This would match the address with the password, (or fail to pass the
mail) and strip the password out.

Mbox format is assumed.

STRING is just a fixed string to make the password easy to egrep.

Something like  DEBIANRULES that prefixes each password.

A 20 character password is assumed, with no spaces.


:0
* ^From.*whoever@whatever.net
{

      :0 B
      * .*STRINGlongpassword
      | sed '/.*STRING[^ ]\{20\}/d' >> <mailqueue file>

}


Alan C.





-- 
      For Linux/Bash users: Eliminate spam with the Mailbox-Sentry-Program. 
         See: http://tinyurl.com/inpd  for the scripts and docs.