sb_chkopts: 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/sb_chkopts - from package: spambayes

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