gpgmailtunl: 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/gpgmailtunl - from package: libgnupg-perl

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

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