On Fri, 25 May 2001, Dave Sill wrote:
>
> No, Received fields aren't randon junk. You can trust the ones added
> by qmail.
>
I guess I will do this after all, I tried uncommenting the call
to env_unset on TCPREMOTEHOST in tcp-env hoping that would do the
trick but it doesn't seem to (I know you said don't touch the source
but it got in my head and I had to try it, you know how it is...)
>
> Nothing easier that parsing the Received fields. E.g., it took me
> about a minute to come up with:
>
> 822field received <msg|sed '1d'|sed '2,$d'|sed 's/.*(//'
>
> Which uses 822field from DJB's mess822 to extract the IP address of
> the sending host from a message.
>
That's really cool. Will grab that package and take a look, thanks.
> >P.S. I take it you are using tmda for your reply-to? I stumbled on this
> >in the course of researching and it looks like just what the doctor
> >ordered for my purposes.
>
> It's great. I've received almost no spam since implementing it. The
> only spam that's gotten through has gone through our "helpful" relay
> which "fixes" unqualified addresses by tacking on "ornl.gov", which is
> on my whitelist, of course.
>
It took me a couple days to come up with a sendmail rule that bounced
email with a "Probably not local" error instead of fixing it like that.
Cuts down on spam drastically, especially on a mail forwarder for
thousands of domains. But not without collateral damage though,
vixie cron job output gets bounced because the from address is
hardcoded as "From: root" into the binary.
-mark
--
mark jeftovic
http://www.easydns.com
http://mark.jeftovic.net
