On Sat, 13 Feb 2010, Per Jessen wrote:
Justin Mason wrote:
It might be useful to compare with MTA MARK and see what the status of
that proposal currently is:
http://tools.ietf.org/draft/draft-stumpf-dns-mtamark/
Amazing. Justin, you must have known about that one - you can't
possibly have just googled it?
Well, I certainly had never heard of this one. And I think that with one
minor variation in concept it could be useful to scoring systems like
SA...
Because of the threat of hacks, any system that 'favors' an MTA is simply
giving spammers a target for exploitation. But an explicit 'disallow'
record (MTA="0") created by the sysadmin would have a similar impact to
deliberately naming PTR records as 'dynamic'. SA could 'detect' the
explicit MTA="0" and add a score (or block outright at MTA level).... The
only thing I would *not* do, given the general laziness of the internet,
is apply any default meaning to the absence of this TXT record. Only
explicit identification of an IP or subnet as 'not permitted to send mail'
would have significance to SA or a blocking MTA.
Hmmmm..... Could work. No impact for non-implementation. Disables an
unauthorized IP for any case where it is used. I like it...
- C
