E-mails being rejected by AT&T
We are a software company with software that many clients use. This software includes functionality for e-mailing customers, whether individually or through automated marketing campaigns (also via automated processes like purchase confirmations). We've received 3 reports in the past month from clients receiving rejected e-mails to @bellsouth.net, @att.net, @sbcglobal.net e-mail addresses and really need this to be resolved. Would someone please help with getting this issue cleared up? We have attempted to write to the [email scrubbed]t address provided in the rejection message but receive no response.
This is the mail system at host xxxxxxxx.info.
I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can delete your own text from the attached returned message.
The mail system
<>: host xxxxxxx.net[xxx.xxx.xxx.xxx] said:
553 5.3.0 flpd570 DNSBL:RBL 521< xxx.xxx.xxx.xxx >_is_blocked.For assistance
forward this error to firstname.lastname@example.org (in reply to MAIL FROM