#!/bin/bash

username=postmaster@mangue-et-solidaire.re
password=
base64=$(echo -ne "\0$username\0$password" | base64)

openssl s_client -starttls smtp -connect mail1.zourit.net:587 -ign_eof <<EOF | grep "Authentication successful"
ehlo mangue-et-solidaire.re
auth plain $base64
quit
EOF