http://www.howtoforge.com/perfect-se...ispconfig-3-p4
12 Install Postfix
Postfix can be installed as follows:
yum install postfix
Then turn off Sendmail and start Postfix:
chkconfig --levels 235 sendmail off
chkconfig --levels 235 postfix on
/etc/init.d/sendmail stop
/etc/init.d/postfix restart
this step gett error
[root@CentOS-63-64-minimal ~]# chkconfig --levels 235 sendmail off
error reading information on service sendmail: No such file or directory
[root@CentOS-63-64-minimal ~]# chkconfig --levels 235 postfix on
[root@CentOS-63-64-minimal ~]# /etc/init.d/sendmail stop
-bash: /etc/init.d/sendmail: No such file or directory
[root@CentOS-63-64-minimal ~]# /etc/init.d/postfix restart
Shutting down postfix: [ OK ]
Starting postfix: [ OK ]