dspam: 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 CentOS possible default full paths are:

/usr/bin/dspam - from package: dspam

You may install the required package with command yum install {package}

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