asmtpd: 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/sbin/asmtpd - from package: mailavenger

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