spamc: 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/spamc - from package: spamassassin

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

On Debian possible default full paths are:

/usr/bin/spamc - from package: spamc

You may install the required package with command apt-get install {package}

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