spfquery.mail-spf-perl: 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
/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/spfquery.mail-spf-perl - from package: spf-tools-perl

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