Background tasks

from django.core.mail import send_mail
from celery import shared_task

@shared_task
def send_welcome_email(user_id):
    user = User.objects.get(id=user_id)
    send_mail(
        'Welcome!',
        'Thanks for joining.',
        'from@example.com',
        [user.email],
    )

# In your view
def signup(request):
    user = User.objects.create_user(...)
    send_welcome_email.delay(user.id)
    return redirect('home')