How to fix Zimbra mail server error: lmdb:/opt/zimbra/conf/postfix_rbl_override is unavailable. open database /opt/zimbra/conf/postfix_rbl_override.lmdb: No such file or directory. To build missing postfix_rbl_override.lmdb file run postmap and zmprov.
# /opt/zimbra/common/sbin/postmap /opt/zimbra/conf/postfix_rbl_override # /opt/zimbra/bin/zmprov mcf +zimbraMtaRestriction 'check_client_access lmdb:/opt/zimbra/conf/postfix_rbl_override'
