swaks: 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/swaks - from package: swaks

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

On Debian possible default full paths are:

/usr/bin/swaks - from package: swaks

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

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