logcheck: 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/sbin/logcheck - from package: logcheck

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

On Debian possible default full paths are:

/usr/sbin/logcheck - from package: logcheck

You may install the required package with command apt-get install {package}

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