> >> > I wonder if there is a way to deactivate the teergrube in Courier
> >> without recompiling?
> >>
> >> Nope.
> >>
> >> > Maybe there is even a way to exclude (whitelist) single IPs from
> >> tarpitting?
> >>
> >> Stripping a mail server of its defenses against hostile peers,
> >> instead of fixing whatever problem causes the peer to shovel crap in
> >> the server's direction, is a rather foolish and a naive decision.
> >>
> >
> > Hi Sam,
> > I _definitely_ agree with you. Courier has been serving us well for
> > years now, teergrube included. The reason why I want to know is, that
> > I want to use a spam filter in front of courier on a separate
> machine.
> > This would be ASSP (assp.sourceforge.net) which works as a proxy. Now
> > if mailserver.somewhere.com wants to send me an email Courier logs
> like this:
> >
> > Nov 14 01:01:16 jupiter courierd:
> > newmsg,id=007174C6.473A3AC6.00007A1F: dns;
> > lists-outbound.sourceforge.net (sirius.netgroup.de
> > [::ffff:195.138.34.209]) [...] Nov 14 01:01:20 jupiter courierd:
> > completed,id=007174C6.473A3AC6.00007A1F
> >
> > If all incoming connections, good or bad, carry the IP of my spam
> > filter then I am afraid of tarpitting my own machine. There are
> > strange delays and I would like to check if tarpitting is the reason.
> 
> Tarpitting would be the reason only if you see actual errors in the
> maillog.
> Only errors are the triggers for any tarpitting.
> 
> I find no reason why you would reject mail from your proxy, provided
> that your proxy only accepts mail for recipient addresses that actually
> exist, and its various settings are not any less liberal than
> Courier's; such as that it does not accept any mail that's larger than
> the maximum size of an email message that Courier is willing to accept.
> 
> 
Yes Sam!
That is exactly the point which hurts.
Being a proxy ASSP "tunnels" the connection from the sending mail server to
my receiving Courier. Courier does the ESMTP dialog.

The bright side: if I set up all MXs as ASSP filters then all MXs will check
with the mailbox server if the recipient exists and spammers' strategy to
pour in junk on the 2nd MX which often has no knowledge of the existing
mailboxes is rendered useless without me having to set up LDAP or the like.

The dark side: while checking for existing recipients the spam filtering
machine _will_ produce errors on bad mail. Will it get punished?

Thanks for your help
Dirk Kulmsee



-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
courier-users mailing list
[email protected]
Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users

Reply via email to