import re
email = ' MACHINE: \nldnmdsbatchxl01\n\n\nMACHINE: p2prog06\n\n\nMACHINE: p1prog\n07'
res = [m.group(1).replace("\n", "").replace("\r", "") for m in re.finditer(r'\bMACHINE:\s*(.*(?:\s*^\d+)?)', email, re.M)]
print(res)
aW1wb3J0IHJlCmVtYWlsID0gJyBNQUNISU5FOiBcbmxkbm1kc2JhdGNoeGwwMVxuXG5cbk1BQ0hJTkU6IHAycHJvZzA2XG5cblxuTUFDSElORTogcDFwcm9nXG4wNycKcmVzID0gW20uZ3JvdXAoMSkucmVwbGFjZSgiXG4iLCAiIikucmVwbGFjZSgiXHIiLCAiIikgZm9yIG0gaW4gcmUuZmluZGl0ZXIocidcYk1BQ0hJTkU6XHMqKC4qKD86XHMqXlxkKyk/KScsIGVtYWlsLCByZS5NKV0KcHJpbnQocmVzKQ==