dotlock.mailutils: 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/dotlock.mailutils - from package: mailutils

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

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