django_outbox_example.py

from django.test import TestCase
from django.core import mail
from myproject.myapp.views import send_some_emails

class FooTestCase(TestCase):

    def test_email_subject(self):
        send_some_emails()
        self.assertEquals(mail.outbox[0].subject, 'My subject')

    def test_send_some_other_emails(self):
        # it's empty in the beginning of every test
        self.assertTrue(len(mail.outbox) == 0)
        send_some_emails()
        self.assertTrue(len(mail.outbox) > 0)