dacsemail: 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 Debian possible default full paths are:

/usr/bin/dacsemail - from package: dacs

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

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