expiry: 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 Debian possible default full paths are:

/usr/bin/expiry - from package: passwd

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

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