We are having a problem with SORBS because of back-scatter NDR, we activate the option to only send NDR if the original message pass SPF, but I think this is not enough.
After some chat with SORBS I receive this response, that explain well the problem:
"This listing was the result of an NDR or bounce message which contained the full body of a spam message. This is a type of spam commonly referred to as "back-scatter." In today's email environment, NDRs and bounces should never quote the body of the original message. This is intended to prevent your mail systems from spamming a spoofed sender address. I recommend updating your configuration to ensure that NDRs do not quote the original message."
Should be possible to disable the original message body included in the NDR, can SM include this option in the future or by default?