gen-ip-validator.pl: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/gen-ip-validator.pl - from package: mimedefang

You may install the required package with command yum install {package}

Error in other languages:
gen-ip-validator.pl: bevel nie gevind nie
gen-ip-validator.pl: comandă negăsită
gen-ip-validator.pl: comando não encontrado
gen-ip-validator.pl: commande introuvable
gen-ip-validator.pl: command not found
gen-ip-validator.pl: käsku ei ole
gen-ip-validator.pl: không tìm thấy lệnh
gen-ip-validator.pl: komanda nerasta
gen-ip-validator.pl: Kommando nicht gefunden.
gen-ip-validator.pl: kommandot finns inte
gen-ip-validator.pl: komut yok
gen-ip-validator.pl: nie znaleziono polecenia
gen-ip-validator.pl: níor aimsíodh an t-ordú
gen-ip-validator.pl: no se encontró la orden
gen-ip-validator.pl: no s'ha trobat l'ordre
gen-ip-validator.pl: opdracht niet gevonden
gen-ip-validator.pl: parancs nem található
gen-ip-validator.pl: perintah tidak ditemukan
gen-ip-validator.pl: príkaz nenájdený
gen-ip-validator.pl: příkaz nenalezen
gen-ip-validator.pl: команда не найдена
gen-ip-validator.pl: командата не е открита
gen-ip-validator.pl: 命令找不到
gen-ip-validator.pl: コマンドが見つかりません