qreceipt: 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/qreceipt - from package: qmail
/var/lib/qmail/bin/qreceipt - from package: qmail

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

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