send-uucp: 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 Debian possible default full paths are:

/usr/lib/news/bin/send-uucp - from package: inn2
/usr/lib/news/bin/send-uucp - from package: inn

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