Kevin, you're probably using your ISP's DNS servers to do the RBL
lookups for you.  Either your operating system is configured with
Covad's DNS servers, or you have your own DNS server configured to do
"DNS forwarding".

What you want to do is run your own DNS server, and NOT have it
configured for "DNS forwarding".  In this way, you won't abuse Covad's
name servers.

Andrew 8)


-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Kevin Rogers
Sent: Thursday, March 31, 2005 2:03 PM
To: [email protected]
Subject: [Declude.Virus] Covad has a problem with our RBL


I received the following email today from Covad - our access provider.  
It looks like they have a problem with Declude checking inbound emails 
against a realtime blackhole list.  (The problem could also be several 
emails we've received lately with hundreds of recipients, many of which 
were invalid - so it could be the NDR problem mentioned). 

Does anyone know if Declude, setup normally without much modification, 
is using more than 1 RBL, or, irregardless of how many it uses, would it

be checking the RBL 12000 times an hour for a mail server that delivers 
about 6000 messages a day?  Or do you think this most likely has to do 
with the too-many-invalid-recipients problem?

Thanks.  Kevin

MESSAGE FOLLOWS
-------------------------------
Dear Covad Customer,

Our records indicate that your computer has made 12497 requests during 
the hour we monitored it which accounted for 5.13% of the total traffic 
to the Covad nameservers in your region. The high volume of requests 
made by your computer to our nameservers causes a degradation of service

for other Covad customers.

The IP address implicated is:

XX.XXX.XXX.XXX

Possible causes for this excessive activity includes, but not limited to

the following reasons:

-Virus infected computer(s) sending infected emails which causes Covad 
servers to receive MX queries for every infected message. -Computer
hosting an open proxy or relay that is being abused by a 
spammer.  Each outbound email will generate a DNS request. -Mail server
configured to check every inbound email on a realtime 
blackhole list (RBL).  This could oppose a problem if there are more 
than two lists being queried.
-Mail server configured to send a non delivery receipt (NDR) for every 
email received at an invalid email address.  NDR messages cause Covad 
servers to receive DNS requests as well as generate unnecessary traffic 
on a customer's network.  NDR messages is also a way for spammers to 
confirm valid email addresses which could cause mail servers to receive 
even more spammed emails.

---
[This E-mail was scanned for viruses.]

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