Here's the working one:
--
[Unit]
Description=Postfix Mail Transport Agent
After=network.target
Conflicts=sendmail.service exim4.service
ConditionPathExists=/etc/postfix/main.cf
[Service]
Type=forking
PIDFile=/var/spool/postfix/pid/master.pid
ExecStart=/usr/sbin/postfix start
ExecReload=/usr/sbin/postfix reload
ExecStop=/usr/sbin/postfix stop
[Install]
WantedBy=multi-user.target
--
I'm not sure if there should be any ExecStartPre entries used since the
postfix command is used instead of the obsolete sysv init script.
