Courier-MTA não está escutando, como aumentar as informações de depuração?

Question

i Siga o tutorial do link

com base no comando systemctl status, o servidor está funcionando bem

# systemctl status courier
courier.service - Courier Daemon
   Loaded: loaded (/usr/lib/systemd/system/courier.service; disabled)
   Active: active (running) since Tue 2013-08-27 15:40:16 WIT; 35s ago
  Process: 509 ExecStop=/usr/sbin/courier stop (code=exited, status=0/SUCCESS)
  Process: 511 ExecStart=/usr/sbin/courier start (code=exited, status=0/SUCCESS)
 Main PID: 516 (courierd)
   CGroup: name=systemd:/system/courier.service
           ├─516 /usr/lib/courier/courierd
           ├─517 /usr/lib/courier/courierd
           ├─518 ./courieruucp
           ├─519 ./courierlocal
           ├─520 ./courierfax
           ├─521 ./courieresmtp
           └─522 ./courierdsn

Aug 27 15:40:16 gravity courierd[517]: Started ./courieruucp, pid=518, maxdels=4, maxhost=4, maxrcpt=16
Aug 27 15:40:16 gravity courierd[517]: Started ./courierlocal, pid=519, maxdels=10, maxhost=4, maxrcpt=1
Aug 27 15:40:16 gravity courierd[517]: Started ./courierfax, pid=520, maxdels=1, maxhost=1, maxrcpt=1
Aug 27 15:40:16 gravity courierd[517]: Started ./courieresmtp, pid=521, maxdels=40, maxhost=4, maxrcpt=100
Aug 27 15:40:16 gravity courierd[517]: Started ./courierdsn, pid=522, maxdels=4, maxhost=1, maxrcpt=1
Aug 27 15:40:16 gravity courierd[517]: queuelo=200, queuehi=400
Aug 27 15:40:16 gravity courierd[517]: Purging /var/spool/courier/msgq
Aug 27 15:40:16 gravity courierd[517]: Purging /var/spool/courier/msgs
Aug 27 15:40:16 gravity courierd[517]: Waiting.  shutdown time=Tue Aug 27 16:40:16 2013, wakeup time=Tue Aug 27 15:50:44 2013, queuedeliverin...rogress=0
Aug 27 15:40:16 gravity courieruucp[518]: ERROR: no uucp user found, outbound UUCP is DISABLED!

mas o servidor não estava escutando

$ sudo netstat -ant | grep :25
$ sudo netstat -ant | grep :143

a configuração inicial

# grep START= /etc/courier/*
/etc/courier/esmtpd:ESMTPDSTART=YES
/etc/courier/esmtpd-msa:ESMTPDSTART=YES
/etc/courier/esmtpd-ssl:ESMTPDSSLSTART=NO
/etc/courier/imapd:IMAPDSTART=YES
/etc/courier/imapd-ssl:IMAPDSSLSTART=NO
/etc/courier/pop3d:POP3DSTART=YES
/etc/courier/pop3d-ssl:POP3DSSLSTART=NO

o log:

Aug 27 15:40:16 gravity courierd: Loading STATIC transport module libraries.
Aug 27 15:40:16 gravity courierd: Courier 0.71 Copyright 1999-2012 Double Precision, Inc.
Aug 27 15:40:16 gravity courierd: Installing [0/0]
Aug 27 15:40:16 gravity courierd: Installing uucp
Aug 27 15:40:16 gravity courierd: Installed: module.uucp - Courier 0.71 Copyright 1999-2012 Double Precision, Inc.
Aug 27 15:40:16 gravity courierd: Installing local
Aug 27 15:40:16 gravity courierd: Installed: module.local - Courier 0.71 Copyright 1999-2012 Double Precision, Inc.
Aug 27 15:40:16 gravity courierd: Installing fax
Aug 27 15:40:16 gravity courierd: Installed: module.fax - Courier 0.71 Copyright 1999-2012 Double Precision, Inc.
Aug 27 15:40:16 gravity courierd: Installing esmtp
Aug 27 15:40:16 gravity courierd: Installed: module.esmtp - Courier 0.71 Copyright 1999-2012 Double Precision, Inc.
Aug 27 15:40:16 gravity courierd: Installing dsn
Aug 27 15:40:16 gravity courierd: Installed: module.dsn - Courier 0.71 Copyright 1999-2012 Double Precision, Inc.
Aug 27 15:40:16 gravity courierd: Initializing uucp
Aug 27 15:40:16 gravity courierd: Initializing local
Aug 27 15:40:16 gravity courierd: Initializing fax
Aug 27 15:40:16 gravity courierd: Initializing esmtp
Aug 27 15:40:16 gravity courierd: Initializing dsn
Aug 27 15:40:16 gravity courierd: Started ./courieruucp, pid=518, maxdels=4, maxhost=4, maxrcpt=16
Aug 27 15:40:16 gravity courierd: Started ./courierlocal, pid=519, maxdels=10, maxhost=4, maxrcpt=1
Aug 27 15:40:16 gravity courierd: Started ./courierfax, pid=520, maxdels=1, maxhost=1, maxrcpt=1
Aug 27 15:40:16 gravity courierd: Started ./courieresmtp, pid=521, maxdels=40, maxhost=4, maxrcpt=100
Aug 27 15:40:16 gravity courierd: Started ./courierdsn, pid=522, maxdels=4, maxhost=1, maxrcpt=1
Aug 27 15:40:16 gravity courierd: queuelo=200, queuehi=400
Aug 27 15:40:16 gravity courierd: Purging /var/spool/courier/msgq
Aug 27 15:40:16 gravity courierd: Purging /var/spool/courier/msgs
Aug 27 15:40:16 gravity courierd: Waiting.  shutdown time=Tue Aug 27 16:40:16 2013, wakeup time=Tue Aug 27 15:50:44 2013, queuedelivering=1, inprogress=0
Aug 27 15:40:16 gravity courieruucp: ERROR: no uucp user found, outbound UUCP is DISABLED!

como aumentar as informações de depuração?