To quote ...
This is the Postfix program at host mail01.powweb.com.
I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.
For further assistance, please send mail to
If you do so, please include this problem report. You can
delete your own text from the message returned below.
The Postfix program
<firstname.lastname@example.org>: host mx.taconic.net[184.108.40.206] said:
552-MessageWall: Message score (1) has reached or exceeded maximum (1):
552- 1 DNSBL-DOMAIN/REJECT: bogusmx.rfc-ignorant.org/optonline.net: Your
domain is listed by a DNS-based blacklist. Please see
http://rfc-ignorant.org/ 552 MessageWall: This message is being rejected
(in reply to end of DATA command)
This effectively blocks anything I send.
I've contacted both of the ISP's with no answer so far.