kmail-migrator: 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/kmail-migrator - from package: kdepim-runtime

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

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