maildirmake.dovecot: 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/maildirmake.dovecot - from package: dovecot-core

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

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