Setting up email with Sendgrid in Heroku for a Django App - django

Question

I am deploying a Django app on Heroku, and using the Sendgrid addon to send out validation email when a user registers on the site.
I followed the instructions here and pasted the following into settings.py:
EMAIL_HOST = 'smtp.sendgrid.net'
EMAIL_HOST_USER = 'sendgrid_username'
EMAIL_HOST_PASSWORD = 'sendgrid_password'
EMAIL_PORT = 587
EMAIL_USE_TLS = True
However, my app is crashing after registration.
What exactly am I supposed to put for EMAIL_HOST_USER and EMAIL_HOST_PASSWORD?
Under the developer's tab in the sendgrid addon in heroku, it gives me the username app*******#heroku.com, and for password it just says "Your Password". Is the password my Heroku password?
Also, do I need to include DEFAULT_FROM_EMAIL in my settings.py file? And where do I tell Sendgrid what it is?
EDIT: I've set DEBUG = True, and it looks like the error is:
SMTPSenderRefused
(550, 'Cannot receive from specified address <info#myapp.com>: Unauthenticated senders not allowed', 'info#myapp.com')
it looks like the problem is happening before Sendgrid does its thing. Do I need to authenticate the email address with Heroku somehow?

Answer 1

Within your settings.py include:
import os
EMAIL_HOST_USER = os.environ['SENDGRID_USERNAME']
EMAIL_HOST= 'smtp.sendgrid.net'
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_PASSWORD = os.environ['SENDGRID_PASSWORD']
Edit: changed EMAIL_PASSWORD to EMAIL_HOST_PASSWORD as that's the correct spelling.

Answer 2

In the intervening 10 years, the above answer has become obsolete. Sendgrid now uses an API key.
https://docs.sendgrid.com/for-developers/sending-email/django
SENDGRID_API_KEY = os.getenv('SENDGRID_API_KEY')
EMAIL_HOST = 'smtp.sendgrid.net'
EMAIL_HOST_USER = 'apikey' # this is exactly the value 'apikey'
EMAIL_HOST_PASSWORD = SENDGRID_API_KEY
EMAIL_PORT = 587
EMAIL_USE_TLS = True