I have followed ur steps to do from Global Settings.
I ran /opt/zimbra/libexec/zmdailyreport -m ... As u said it was some issue lying there no more messages coming in /var/spool but i dint get in the inbox...
zimbra.log shows:
Oct 15 08:35:56 mta postfix/smtpd[28920]: NOQUEUE: reject: RCPT from mbhostname: 554 5.7.1 <zimbra@mbhostname>: Sender address rejected: Access denied; from=<zimbra@mbhostname> to=<admin@domain.com> proto=ESMTP helo=<localhost.localdomain>
Oct 15 08:35:56 mta postfix/smtpd[28920]: warning: non-SMTP command from mbhostname: Subject: Daily mail report from 2009-10-14 00:00:00 to 2009-10-15 00:00:00
Oct 15 08:35:56 mta postfix/smtpd[28920]: disconnect from mbhostname
the log shows
zimbra@mbhostname.com