spfmilter: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/spfmilter - from package: spf-milter-python

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