crosspost: 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/lib/news/bin/crosspost - from package: inn

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

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