makeuucpneighbors: 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/makeuucpneighbors - from package: courier-mta

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

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