ifile.inject-learn.header: 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/share/doc/ifile/examples/ifile.procmail-0.2/bin/ifile.inject-learn.header - from package: ifile

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

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