smrsh: 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/sbin/smrsh - from package: sendmail

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

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