systemctl status postfix
Unit postfix.service could not be found.
現在のステータスが帰ります
● postfix.service - Postfix Mail Transport Agent
Loaded: loaded (/usr/lib/systemd/system/postfix.service; enabled; vendor preset: disabled)
Active: inactive (dead)
yum -y install postfix
vi /etc/postfix/main.cf
systemctl restart postfix