horde-crond: 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/horde-crond - from package: php-horde-horde

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

On Debian possible default full paths are:

/usr/bin/horde-crond - from package: php-horde

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

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