Heads up for spamhaus.org problems

[Gareth]

On Tue, 2007-08-21 at 01:53, Richard Potter wrote:
> On Mon, Aug 20, 2007 at 11:34:05PM +0200, Alex Broens wrote:
> 
> > On 8/20/2007 11:22 PM, Tim Boyer wrote:
> > >On Sun, 19 Aug 2007 22:02:01 -0400, Richard Potter <rpotter at rpcs.net> 
> > >wrote:
> > >
> > >>On Mon, Aug 20, 2007 at 12:34:23AM +0200, Raymond Dijkxhoorn wrote:
> > >>
> > >>>>Just doing a routine check here, and I have a few mail servers 
> > >>>>misbehaving. It
> > >>>>*appears* sendmail dnsbl to zen.spamhaus.org is timing out, and causing 
> > >>>>mail
> > >>>>delivery delays, or none at all.
> > >>>>
> > >>>>I'm going to discontinue spamhaus, and see what happens.
> > >>>Buy rsync from them. Most likely you fire a lot of lookups on their 
> > >>>servers and they started to ban high volume mailservers some time ago.
> > >>>We have seen this in a lot of places allready.
> > >>>
> > >>>May i ask how much mail are you processing daily?
> > >>Thanks for the reply Raymond.. I wasn't aware they were doing that. These
> > >>are low volume servers, less than 2,000 messages per day. Does that count
> > >>as "high volume" to spamhaus?
> > >>
> > >>Richard
> > >
> > >"Use of the Spamhaus DNSBLs via DNS queries to our public DNSBL mirrors is 
> > >free
> > >for low-traffic mail servers serving less than 100 users. Use of the 
> > >Spamhaus
> > >DNSBLs by commercial or corporate networks, ISPs and ESPs, requires a
> > >subscription to Spamhaus's Data Feed service."
> > >
> > >I'd be shocked if 2,000 messages per day counts as high volume.  That's 20
> > >emails per person per day.
> > 
> > no need to be shocked :-)
> > 
> > Spamhaus can't block your mail server from doing queries - it blocks 
> > your DNS' access to the root zone - so if you use a DNS which is 
> > querying Xmillion queries/day and your server is only doing 10000/day 
> > then the rest of the X/million+your 10000 makes he count which rates a 
> > block.
> 
> 
> You are exactly right. I was told that off list. I switched the two 
> boxes to an alternative DNS server, and spamhaus worked again.
> 
> I'm not sure why I didn't figure that out on my own. I actually 
> knew/should have known that. It was Sunday, and I might have had a 
> few beers! :-)
> 
> Richard

When I was blocked for 2000 messages/day I was running a caching
nameserver on the local box and no queries were forwarded elsewhere.