[Answered ]-Can't send an email in Django 1.9

As the Django doc mentioned,

Django runs through each URL pattern, in order, and stops at the first one that matches the requested URL.

The call of /contact/auth/ first matched by /contact, and you did not offer the post function in your ContactView, that’s why you got 405. So there are two way to fix this:

1

Simply change /contact/auth/ to /contact123/auth/(note the trailing slash).

I recommend you write like this:

url(r'^contact123/auth/', views.send_email, name='post_url'),

and this:

<form action="{% url 'post_url' %}" method="post">
...

This will make the change of you url pattern much more easier.

2.

Add the trailing $ like this url(r'^contact/$', views.ContactView.as_view(), name='contact'),.

Either two way worked fine as I tested.