listadmin: 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
/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/listadmin - from package: listadmin

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