Code:
root@zimbra:~# su - zimbra
zimbra@zimbra:~$ zmlocalconfig -e ldap_postfix_password=mypassword
zimbra@zimbra:~$ zmldappasswd -p mypassword
Updating local config and directory
zimbra@zimbra:~$ zmmtactl stop; zmmtactl start
postfix/postfix-script: stopping the Postfix mail system
..many messages...all seem to be just confirmations...
zimbra@zimbra:~$ tail -f /var/log/zimbra.log
May 7 12:26:56 zimbra postfix/postfix-script[8677]: warning: not owned by root: /opt/zimbra/postfix-2.4.7.5z/conf/main.cf
May 7 12:26:56 zimbra postfix/postfix-script[8690]: starting the Postfix mail system
May 7 12:26:56 zimbra postfix/master[8691]: daemon started -- version 2.4.7, configuration /opt/zimbra/postfix-2.4.7.5z/conf
May 7 12:26:57 zimbra saslauthd[8731]: detach_tty : master pid is: 8731
May 7 12:26:57 zimbra saslauthd[8731]: ipc_init : listening on socket: /opt/zimbra/cyrus-sasl-2.1.22.3z/state/mux
May 7 12:26:57 zimbra postfix/pickup[8697]: E973BD6825A: uid=1002 from= orig_id=8D55AD68252
May 7 12:26:57 zimbra postfix/trivial-rewrite[8762]: warning: dict_ldap_connect: Unable to bind to server ldap://zimbra.server:389 as uid=zmpostfix,cn=appaccts,cn=zimbra: 49 (Invalid credentials)
May 7 12:26:57 zimbra postfix/trivial-rewrite[8762]: warning: dict_ldap_connect: Unable to bind to server ldap://zimbra.server:389 as uid=zmpostfix,cn=appaccts,cn=zimbra: 49 (Invalid credentials)
May 7 12:26:58 zimbra postfix/cleanup[8701]: warning: dict_ldap_connect: Unable to bind to server ldap://zimbra.server:389 as uid=zmpostfix,cn=appaccts,cn=zimbra: 49 (Invalid credentials)
May 7 12:26:58 zimbra postfix/cleanup[8701]: warning: E973BD6825A: sender_canonical_maps map lookup problem for user@external.domain