sendmailconfig: 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/sendmailconfig - from package: sendmail-base

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

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