purgestat: command not found

Have You tried accessing the binary with the full path?

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/purgestat - from package: sendmail

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

On Debian possible default full paths are:

/usr/sbin/purgestat - from package: sendmail-bin

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