Hostname/DNS "A Record" name

[dschaldedfg]

We are having an issue with one domain bellsouth.net we are basically getting this back from them.

12:18:29 928 MSG 10801 Recipient: rfleming06@bellsouth.net
12:18:30 888 DMN: MSG 10802 Send Failure: 521 Error - Blocked for abuse. Contact abuse_rbl@abuse-att.net.
12:18:30 888 DMN: MSG 10802 Send Failure: 521 Error - Blocked for abuse. Contact abuse_rbl@abuse-att.net.
12:18:59 480 MSG 10803 Analyzing result file: /media/nss/MAIL/ndhdom/wpgate/gwia/result/rae59395.645
12:18:59 480 MSG 10803 Detected error on SMTP command
12:18:59 480 MSG 10803 Command: bellsouth.net
12:18:59 480 MSG 10803 Response: 521 Error - Blocked for abuse. Contact abuse_rbl@abuse-att.net.


When I looked up the Detected error on SMTP command, I found some information about the Hostname, currently on our server it is setup as Hostname/DNS "A Record" name: ndhc.org (according to the internet domain holder (godaddy) the host name is ndhc.org and the "A" record name is mail. What should we have in the Hostname/DNS "A Record" name field? I believe that we have tried the servername.domain name (liberxx.ndhc.org) and that failed and I think that we also tried (mail.ndhc.org) I cannot confirm that we actually have it has been awhile since we did this project, but I am just wondering if someone can help clear this up for me. Thank you. This issue only started happen with Bellsouth.net when we switched from the NetWare GWIA to the Linux GWIA is there something else that might have been missed.