I have a Zimbra 7.1.4 as mailbox, and now I have added a second zimbra (7.2) as mta standalone (no role mta) and is working ok as incoming and outcoming mails, but I have one problem:
I have detected that my ip has been added to backscatterer black list, it seems that the problem is that accounts that not exists are generating mail that can cause spam problems.
I have read Improving Anti-spam system - Zimbra :: Wiki and I have added in mailbox in zmmta.conf
POSTCONF smtpd_reject_unlisted_recipient yes

but mta always allow to receive all mail (also accounts that doesn't exist).
What are the possible solutions?
- add an script to generate a relay_recipient_amps to zimbra, and export and load to zimbra mta?
- filter bounce mails and not to send?
- other options?

What can I do to solve this problem of backscattere in this installation?