which service shall I turn off

[rawandnet]

my linux server run postfix and mailscanner only and need ssh for remote login. the following services below are running on my system. I want to titan the server security, what service shall I trun off?

MailScanner on
acpid on
anacron on
atd on
auditd on
autofs on
avahi-daemon on
bluetooth on
cpuspeed on
crond on
cups on
gpm on
haldaemon on
hidd on
hplip on
ip6tables on
iptables on
irqbalance on
iscsi on
iscsid on
isdn on
kudzu on
libvirtd on
lvm2-monitor on
mcstrans on
mdmonitor on
messagebus on
microcode_ctl on
netfs on
network on
nfslock on
pcscd on
portmap on
rawdevices on
readahead_early on
restorecond on
rhn-virtualization-host on
rhnsd on
rpcgssd on
rpcidmapd on
setroubleshoot on
smartd on
sshd on
syslog on
xend on
xendomains on
xfs on
xinetd on
yum-updatesd on

[Rubberman]

Are you running virtual machines on this host? If not, you can remove the xen kernel and xen tools which will automatically disable all the xen and related services. As far as I can see, most (or all) of the other services are necessary (or desirable) for your system. Disabling them will quickly illustrate the "law of unintended consequences" with a non-functional or otherwise broken system.