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RE: Fun new policy at AOL
From: "R. Benjamin Kessler" <bk-lists () kesslerconsulting com>
Date: Thu, 28 Aug 2003 15:57:19 -0500


Does the IP address of your client's SMTP server have a reverse DNS entry
(PTR record) assigned to it?

It seems to be a new "best practice" to not accept e-mail from an IP address
that doesn't have a PTR record assigned.  Furthermore, if those PTR records
indicate anything like "dial" "dns" "cable" then more 'strict' policies tend
to reject them.

If you can't get your upstream to modify the PTR records to your
specifications (or delegate the block to you) then another way around this
would be to configure your client's SMTP server to forward to the provider's
"smart host" (e.g. a SMTP relay server with a known address and appropriate
PTR record configured to accept relay traffic from customer IP's).  Not the
most elegant but a serviceable workaround none the less.

HTH

Ben

~~~~~~~~~~
R. Benjamin Kessler
Network Engineer
CCIE #8762, CISSP, CCSE
Kessler Consulting
Email:  ben () kesslerconsulting com
http://www.kesslerconsulting.com
Phone: 260-625-3273
 

-----Original Message-----
From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of
Susan Zeigler
Sent: Thursday, August 28, 2003 2:35 AM
To: nanog () merit edu
Subject: Fun new policy at AOL


Sometime mid last week, one of my clients--a state chapter of a national
association--became unable to send to all of their AOL members. Assuming
it was simply that AOLs servers were inundated with infected emails, I
gave it some time. The errors were simply "delay" and "not delivered in
time specified" errors.

Well, it was still going on today. So, I went on site and upped the
logging on the server. What to my surprise did appear but a nice little
message informing us that "I'm sorry, your IP is dynamically assigned
and aol doesn't accept dynamic IPs. 

WTF. This IP is NOT dynamic. The client has had it for about two years.

I just looked on their website to file a complaint and ask how they
determined what was dynamic and what was static and couldn't find a
contact email address. I did find the following statement:
"AOL's mail servers will not accept connections from systems that use
dynamically assigned IP addresses."

It was on the following page:
http://postmaster.info.aol.com/standards.html

So, since I know someone from AOL does lurk on this list, what's my
recourse. Feel free to email me offlist. Thanks. 

On a side note, my client is also curious who's going to help pay the
bill that they shouldn't have needed to pay me due to AOL changing
policy and blocking them needlessly. Unless AOL is downloading the
entire routing pools from all ISPs on a daily basis, how do they know
which IPs are dynamic and which are static;) And, since static IPs can
actually be assigned out of a DHCP pool as well, even that won't work.

-- 

-- 

--
-Susan
--
Susan Zeigler             |      Technical Services
szeigler () spindustry com   |      Spindustry Systems
515.225.0920              |      

"You cannot strengthen the weak by weakening the strong." 
-- Abraham Lincoln


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DES MOINES / CHICAGO / INDIANAPOLIS / DENVER 

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