smbclient: 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/smbclient - from package: samba4-client
/usr/bin/smbclient - from package: samba-client

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

On Debian possible default full paths are:

/usr/bin/smbclient - from package: smbclient

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

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