Django email not working - smtplib.SMTPServerDisconnected: Connection unexpectedly closed

I'm using the standard Django/SendGrid setup for sending emails. Here's the relevant fields in my settings.py:

EMAIL_HOST = 'smtp.sendgrid.net'
EMAIL_HOST_USER = 'myusername'
EMAIL_HOST_PASSWORD = 'mypassword'
EMAIL_PORT = 465
EMAIL_USE_SSL = True
DEFAULT_FROM_EMAIL = 'admin@mysite.com'

I'm testing sending emails in my shell by executing:

send_mail('test','test','email@email.com',['to@email.com'])

however, it returns this error Traceback:

Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/Users/zorgan/Desktop/app/lib/python3.5/site-packages/django/core/mail/__init__.py", line 62, in send_mail
    return mail.send()
  File "/Users/zorgan/Desktop/app/lib/python3.5/site-packages/django/core/mail/message.py", line 348, in send
    return self.get_connection(fail_silently).send_messages([self])
  File "/Users/zorgan/Desktop/app/lib/python3.5/site-packages/django/core/mail/backends/smtp.py", line 104, in send_messages
    new_conn_created = self.open()
  File "/Users/zorgan/Desktop/app/lib/python3.5/site-packages/django/core/mail/backends/smtp.py", line 71, in open
    self.connection.login(force_str(self.username), force_str(self.password))
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/smtplib.py", line 720, in login
    initial_response_ok=initial_response_ok)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/smtplib.py", line 630, in auth
    (code, resp) = self.docmd("AUTH", mechanism + "" + response)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/smtplib.py", line 420, in docmd
    return self.getreply()
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/smtplib.py", line 393, in getreply
    raise SMTPServerDisconnected("Connection unexpectedly closed")
smtplib.SMTPServerDisconnected: Connection unexpectedly closed

Any idea why I'm getting this error?

PS: This is my local development server