export.py: 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 CentOS possible default full paths are:

/usr/lib/mailman/bin/export.py - from package: mailman

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/lib/mailman/bin/export.py - from package: mailman

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

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