[COLUG] another anti-spam link

[Rob Funk]

Duane wrote:
> Came across this link today and I wasn't even looking for stuff on this
> topic, but that's how I seem to come across numerous interesting links.
>
> http://www.gabacho-net.jp/en/anti-spam/anti-spam-system.html
>
> Basically a white paper/broad overview and a big list of regular
> expressions for postfix of common hostnames that probably shouldn't be
> sending mail, or should have set a better reverse lookup.

If I'm understanding this correctly (and I may not be), it seems to be an 
approximate superset of to using the RBLs of dynamically-allocated 
addresses; this looks like the generic rules would catch even 
statically-allocated addresses assigned my ISPs.  But there are people 
out there (I know at least two) who run legitimate mail servers from 
their homes yet have no control over their reverse-DNS lookup.  (One of 
those I know doing this is technically violating his ISP's TOS, the other 
paid for a static address.)

> Most of the rules reject the email with a 450 status to take into
> account transient issues with things like DNS, rather then rejecting
> things out right completely.

But if their DNS doesn't change before they come back, they continue 
getting rejected on every retry.  It would make sense if this were linked 
with greylisting (whitelisting anyone who retries), but it doesn't appear 
to be.


-- 
==============================|   "A microscope locked in on one point
 Rob Funk <rfunk at funknet.net> |Never sees what kind of room that it's in"
 http://www.funknet.net/rfunk |    -- Chris Mars, "Stuck in Rewind"