i would like to ask for help to troubleshoot a problem in my mail server.
i have enabled a settings "- hostaname in greeting (reject unknown reverse _client hostaname)" in MTA of Zimbra Administration in order to enforce SPAM filter.
Now my SMTP is blocking some e-mails with the error server postfix/smtpd[15667]: NOQUEUE: reject: RCPT from unknown[1.2.3.4]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [1.2.3.4], which we traced back to the reject_unknown_client_hostname. As it happens, the hostname to which the reverse address resolves does not, itself, have a DNS record. The chances of getting this fixed are low, but we do need to get their e-mail.
So, can we configure some sort of exception to get around this rule just for them?
My Environment has:
Zimbra OSE 8.6 p3
Linux ubuntu 14.04 x64
Regards