poppassd: 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/sbin/poppassd - from package: poppassd

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

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