class Configuration(models.Model):
    email_use_tls = models.BooleanField(_(u'EMAIL_USE_TLS'),default=True)
    email_host = models.CharField(_(u'EMAIL_HOST'),max_length=1024)
    email_host_user = models.CharField(_(u'EMAIL_HOST_USER'),max_length=255)
    email_host_password = models.CharField(_(u'EMAIL_HOST_PASSWORD'),max_length=255)
    email_port = models.PositiveSmallIntegerField(_(u'EMAIL_PORT'),default=587)
    ....

from django.core.mail import EmailMessage
from django.core.mail.backends.smtp import EmailBackend


config = Configuration.objects.get(**lookup_kwargs)

backend = EmailBackend(host=config.host, port=congig.port, username=config.username,
                       password=config.password, use_tls=config.use_tls, fail_silently=config.fail_silently)

email = EmailMessage(subject='subj', body='body', from_email=from_email, to=to,
             connection=backend)

email.send()

backend = EmailBackend(host=config.host, port=congig.port, username=config.username,
                               password=config.password, use_tls=config.use_tls, fail_silently=config.fail_silently)
email = EmailMessage(subject='subj', body='body', from_email=from_email, to=to,
                 connection=backend)

$ pip install django-des

INSTALLED_APPS = (
    ...
    'django_des',
    ...
)

EMAIL_BACKEND = 'django_des.backends.ConfiguredEmailBackend'

from django_des import urls as django_des_urls

urlpatterns = [
    ...
    url(r'^django-des/', include(django_des_urls)),
]