email - setup mail on centos

when I try to send mail on centos:
mail -s "hello" root

to=root, ctladdr=root (0/0), delay=00:00:00\ , xdelay=00:00:00, mailer=relay, pri=30031, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Con\ nection refused by [127.0.0.1]

my question is:
1. do I need to setup a smtp mail server on localhost for mail to work?

Answer

Yes. There are plenty of HOWTOs on configuring sendmail, but iirc CentOS comes out of the box ready to run a working sendmail (for sending) on localhost. Try

chkconfig --list sendmail

and if it's not running,

chkconfig sendmail on
service sendmail start

and try again.