dbmail-timsieved: 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/sbin/dbmail-timsieved - from package: dbmail

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