[100899] in North American Network Operators' Group
Re: unwise filtering policy from cox.net
daemon@ATHENA.MIT.EDU (Sean Donelan)
Wed Nov 21 01:37:25 2007
Date: Wed, 21 Nov 2007 01:33:37 -0500 (EST)
From: Sean Donelan <sean@donelan.com>
To: "'nanog@merit.edu'" <nanog@merit.edu>
In-Reply-To: <Pine.LNX.4.64.0711201118070.9033@sasami.anime.net>
Errors-To: owner-nanog@merit.edu
On Tue, 20 Nov 2007, goemon@anime.net wrote:
> <abuse@cox.net>
> (reason: 552 5.2.0 F77u1Y00B2ccxfT0000000 Message Refused. A URL in
> the content of your message was found on...uribl.com. For resolution do
> not contact Cox Communications, contact the block list administrators.)
An unfortunate limitation of the SMTP protocol is it initially only
looks at the right-hand side of an address when connecting to a
server to send e-mail, and not the left-hand side. This means
abuse@example.com first passes through the same server as all of
the rest of *@example.com e-mail. A single high-volume or special
address can easily overwhelm the normal email infrastructure (i.e. mailbox
full) or the normal server administrators may make changes which affects
all addresses passing through that server (i.e. block by IP address).
Even the FTC's UCE uce@ftc.gov e-mailbox has had problems, which
affected the rest of *@ftc.gov e-mail. So the FTC created a separate
right-hand side name spam@uce.gov to separate UCE reports from normal
FTC e-mail channels which lets them route the mail with separate mail
handling policies based on the right-hand side.
