smtpsearch: 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 Debian possible default full paths are:

/usr/bin/smtpsearch - from package: libruli-bin

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