the authors of RFC 2317 have a question for at&t worldnet

(this must be my week for past-sins pennance related to RBL's.)

today someone whose e-mail was blocked when they tried to send it to an at&t
customer, asked the authors of RFC 2317 to please unblock their address. as
the only such author whose e-mail address hasn't changed since RFC publication
i pretty much assumed that the other two guys weren't hearing this, and so i
investigated. the complainer showed me this text:

  <>: host[] said:
    550- blocked by ldap:ou=rblmx,dc=worldnet,dc=att,dc=net 550
    Blocked for abuse. See"
    (in reply to MAIL FROM command)

i looked at the URL thus indicated, and the link for

  Information for end-users whose messages have been blocked.


which says:

  What to do: Ask your system administrator to submit identifying information
  to the DNS. For more information, your administrator should refer to In the meantime, you should use a
  fully registered domain for sending your messages, such as the mail system
  from an ISP or one of the major free e-mail services.

now, i count myself as a master of the obscure reference, but this is over
the top. can someone from at&t worldnet please contact me for the purpose
of explaining what RFC 2317 could possibly have to do with spam complaints?

(and btw, if you're going to block inbound e-mail, you need to give senders
some idea of how to get unblocked. not for fairness, just for practicality.
and this parenthesized paragraph is why i count this screed as not-off-topic.)

I'm not from AT&T, but that page contains three errors and three "What to do" sections. The section referring to RFC 2317 is for DNS errors:

�550 Error. Blocked for status: <unknown sender>�: This error indicates that no identifying information has been entered into the DNS (Domain Name System) for this sending system. The AT&T Worldnet mail system, like many others, does not accept messages from mail systems with no DNS records.

The "Spam complaint" section has a different "What to do:"

What to do: Ask the administrator of your mail system to contact us through our System Administrators' page and provide the information we need to investigate the problem.

Paul Vixie wrote:

Putting on my sender hat, I see that the URL you link to leads one to:

I've had some client issues in the past that have necessitated use of
that process. I have found that AT&T is fairly responsive regarding
sender blocking issues. There are many other ISPs whom I wish were as
good at publishing info and offering a contact channel.

Al Iverson