mail transfer agent
sed -i "/postfix/d" /etc/passwd
sed -i -e "/postfix/d" -e "/postdrop/d" /etc/group
echo "postfix:x:8:8:postfix::/bin/false" >> /etc/passwd
echo "postfix:x:8" >> /etc/group
echo "postdrop:x:9:" >> /etc/group
newaliases
postmap /etc/postfix/access
postmap /etc/postfix/canonical
postmap /etc/postfix/generic
postmap /etc/postfix/relocated
postmap /etc/postfix/transport
postmap /etc/postfix/virtual
sed -i "/postfix/d" /etc/passwd
sed -i -e "/postfix/d" -e "/postdrop/d" /etc/group