maidag: 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/sbin/maidag - from package: mailutils

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