kgpgconf: 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 CentOS possible default full paths are:

/usr/bin/kgpgconf - from package: kdepim

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/kgpgconf - from package: kleopatra

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

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