dspam_admin: 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 CentOS possible default full paths are:

/usr/bin/dspam_admin - from package: dspam

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