eximon: 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/eximon - from package: exim-mon

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

On Debian possible default full paths are:

/usr/sbin/eximon - from package: eximon4

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

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