[root@localhost ~]# service sendmail start
You have new mail in /var/spool/mail/root
[root@localhost ~]# yum install -y sendmail
Loaded plugins: fastestmirror, security
Loading mirror speeds from cached hostfile
* base: mirror.steadfast.net
* extras: mirror.steadfast.net
* rpmforge: mirror.us.leaseweb.net
* updates: mirror.steadfast.net
Setting up Install Process
Package sendmail-8.14.4-8.el6.x86_64 already installed and latest version
Nothing to do
You have new mail in /var/spool/mail/root
[root@localhost ~]# service sendmail restart
Shutting down sm-client: [ OK ]
Shutting down sendmail: [ OK ]
Starting sendmail: [ OK ]
Starting sm-client: [ OK ]
You have new mail in /var/spool/mail/root