imapfront-auth: 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/sbin/imapfront-auth - from package: mailfront

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

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