North American Network Operators Group

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Re: unwise filtering policy from cox.net

  • From: Sean Donelan
  • Date: Wed Nov 21 01:38:31 2007


On Tue, 20 Nov 2007, goemon@xxxxxxxxx wrote:
<abuse@xxxxxxx>
(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@xxxxxxxxxxx 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@xxxxxxx 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@xxxxxxx 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.