burst: 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/mu-mh/burst - from package: mailutils-mh
/usr/bin/mh/burst - from package: nmh

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

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