[Django]-Django models, signals and email sending delay

The easiest thing is to queue the email messages and then have them sent by a daemon. Check out django-mailer.

Since you only seem to be concerned with send_mail, you can get started with two steps. First, use this to import django-mailer’s version of send_mail:

# favour django-mailer but fall back to django.core.mail
from django.conf import settings

if "mailer" in settings.INSTALLED_APPS:
    from mailer import send_mail
else:
    from django.core.mail import send_mail

And then create a cronjob that calls manage.py send_mail to send the mail. Check the django-mailer usage docs for example cronjob entries.

If you are not seeing any email get sent, try running manage.py send_mail on the console. This seems to be the number one problem people have.