cvm-qmail: 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/cvm-qmail - from package: cvm

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

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