opendkim-reportstats: 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/sbin/opendkim-reportstats - from package: opendkim

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

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