Heads up for spamhaus.org problems

Richard Potter rpotter at rpcs.net
Tue Aug 21 01:53:42 IST 2007

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! :-)


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