安装Qmail遇到的问题?

wuxiabo

系统环境: Redhat 9.0
在安装Qmail时,提示没有perl5,我在网上找了几天,也没找到怎样把perl5安装上去，perl5有什么作用？怎样才能正常安装完qmail.

[root@R9000 Qmail_setup]# ./setup
Checking...for gcc
/usr/bin/gcc
Checking...for g++
/usr/bin/g++
Checking...for make
/usr/bin/make
Checking...for perl5
which: no perl5 in (/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin)
Sorry,Your system not perl5 program!