smproxy: command not found

Have You tried accessing the binary with the full path?

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

[root@server ~]# echo $PATH

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/smproxy - from package: x11-session-utils

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