Security Basics mailing list archives

RE: Sorbs.net DNS Blacklist


From: "Dan Tesch" <dan.tesch () comcast net>
Date: Fri, 10 Mar 2006 18:38:09 -0600

 
Sorbs? I hope someone takes them down.  I have a client that uses SBC and
they way their IP range was
named was an issue for Sorbs - this was rectified and now it's that the MX
record TTL isn't right - the
DNS records are hosted for now with Network Solutions who won't change the
TTL - lots of bounce backs!
AAAAAARRRRRRRRRRRGGGGGGGGGGHHHHHHHH!!!!!!!!!!!

I've got some updated info since the original posting. I spoke by email with
a gent at payments () sorbs net, and was told that the reason we were
blacklisted was that a spammer sent a message from a forged username at a
particular domain. The email hit an address at our server that was no longer
in use, and of course a bounce message was sent back saying the address
doesn't exist. 

Evidently, this response is considered spam in and of itself by sorbs.net,
and that's what got us on the blacklist. Never mind that we were the ones
who got spammed in the first place, and our mail gateway was only doing what
it was supposed to do. I was told that if we ceased such "harassment", then
we would be removed from the blacklist. 

Symantec, who makes our gateway, has it documented on their website that
this feature cannot be disabled, and that such responses are required by RFC
821. I can see the point. If there's no response to the sender of an email
who accidentally puts a typo in the email address they're sending to, how
the heck would they know if their email reached the correct party or not?
They'd receive no response from a real user, and they'd probably wonder why
they're being ignored. In a business setting, that behavior could lose you
money real quick.

Can anyone please let me know if I'm the one being over-the-top here?
I'd also still like to hear other people's input or experience with these
folks.

-----Original Message-----
From: Dan Denton
Sent: Thursday, March 09, 2006 9:31 AM
To: security-basics () securityfocus com
Subject: Sorbs.net DNS Blacklist


Does anyone on the list have any prior experience with the folks at
sorbs.net? For the past few weeks a customer who uses a blacklist
supplied by them has had our emails blocked. Previous to this the
company had no problem getting our emails. People at said company want
to receive our emails and are frustrated that they can't receive them
(important stuff like invoices and statements), but their IT admin says
he has no control over the list itself. 

I went to sorbs.net, checked our status using one of their utilities,
and the IP of our mail server shows up on their list. I've even sent in
a request to be removed from the list and have received a ticket number.
In their procedures for delisting, they claim that you must "donate" $50
per email they supposedly received in their spam traps, and the
donations are to be made to 2 charities of their choice. I for one think
this is extortion, regardless of whether the intention is to stop
spammers.

Any background or experience you can share would be appreciated. Thanks
in advance...

Dan Denton

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---------------------------------------------------------------------------
EARN A MASTER OF SCIENCE IN INFORMATION ASSURANCE - ONLINE
The Norwich University program offers unparalleled Infosec management 
education and the case study affords you unmatched consulting experience. 
Tailor your education to your own professional goals with degree 
customizations including Emergency Management, Business Continuity Planning,

Computer Emergency Response Teams, and Digital Investigations. 

http://www.msia.norwich.edu/secfocus
---------------------------------------------------------------------------


---------------------------------------------------------------------------
EARN A MASTER OF SCIENCE IN INFORMATION ASSURANCE - ONLINE
The Norwich University program offers unparalleled Infosec management 
education and the case study affords you unmatched consulting experience. 
Tailor your education to your own professional goals with degree 
customizations including Emergency Management, Business Continuity Planning, 
Computer Emergency Response Teams, and Digital Investigations. 

http://www.msia.norwich.edu/secfocus
---------------------------------------------------------------------------


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