Question : Exchnage IP address blocked by sbcglobal.net

I have a client that has recently moved. Since the move, they are unable to send email to sbcglobal.net recipients. I have the ISP create a reverse DNS and the sending domain does not appear to be blacklisted. Here is a copy of the tag from the bounce back message:

<jjfieldservices.com #5.3.0 smtp;553 5.3.0 nlpi112 - o65Hd6IA027563, DNSBL:ATTRBL 521<          24.249.159.236 >_is_blocked.__For_information_see_http://att.net/blocks>

I've looked up the error code:521. It says basically we've been tagged as spam. The network is clean. I requested to be removed and this is the response I got back:

Thank you for contacting the AT&T Postmaster.
We do not show that the IP address(es) you have listed in your request are on the block list.  This result may be due to the
following:
- This IP may have already been marked for removal by the postmaster staff as a result of another request via the webform located at http://att.net/blocks, or an email request sent to [email protected].
- The IP address referenced in your webform request is NOT the IP address that is blocked.  Please make sure that you entered the IP address of the blocked mail server in the first field of the webform request page.  This information is included in the error message returned when a blocked mail server attempts to deliver mail to any AT&T customer.
- The information you entered into the webform is NOT an canonical IP address, or is a range of IP addresses.
If you are not the mail administrator of the blocked IP address, please forward this letter to them.
ADMINISTRATORS:
Please visit http://att.net/blocks, or mail to <[email protected]> a complete and current copy of the error message received when mail is blocked at our network.  If your server truncates any part of the error message containing the blocked IP address, please conduct a manual session(telnet) with our mail server and capture the full text of the error message.
Your issue may not be resolved without this error message.
Please thoroughly check your IP logs before requesting removal.  
You must determine that all traffic from the blocked IP is actually from your mail servers to ensure your network is not compromised.  
Administrators who fail to do this may experience subsequent and more resolute blocking.
Regards,
AT&T Postmaster
AT&T CSO/IISS
[email protected]
http://att.net/blocks

This is turning into a pretty big issue for my client as they need to email their clients on a regular basis. That's pretty much the entire nature of their business actually. Any help is greatly appreciated. Thanks in advance!

Answer : Exchnage IP address blocked by sbcglobal.net

I called Cox to see if they new anything about it. The tech stated that they have been having this problem for the last couple of weeks, but there was nothing that they could do to keep us from being blocked. lol. She said that if they hosted our email that we could relay our mail through a Cox smart host. I said that Exchange has a setting for smart host relay. She said yea but it doesn't work, according to her boss. lol. I had her give me the settings and I set it up in Exchange. So far no bounce back. :)

I will give it a few hours to make sure all is good. If all works, should I inform Cox on how to resolve this issue and let them know that the relay actually does work?? lol