sharedindexinstall: 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 Debian possible default full paths are:

/usr/sbin/sharedindexinstall - from package: courier-base

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

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