django2.1 send email fail:ssl.SSLError: [SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:833)

Question

I want to send email to myself, so I tried it. I had set my email info in settings.py

EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_USE_TLS = False 
EMAIL_USE_SSL = True   
EMAIL_HOST = 'smtp.163.com'  
EMAIL_PORT = 25     
EMAIL_HOST_USER = '*****@163.com'    
EMAIL_HOST_PASSWORD = '***'   

then I write down the example from django document

from django.core.mail import send_mail

send_mail(
    'Subject here',
    'Here is the message.',
    'from@example.com',
    ['to@example.com'],
    fail_silently=False,
)

then a exception happened

ssl.SSLError: [SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:833)

How to fix it?

Answer 1

You should check that you are using the correct port number.

You probably need to change the port from 25 to 465 or 587 to use SMTP with SSL; port 25 is often used for non-encrypted email. Of course, it depends on your email provider, but it is kind of a standard followed by most providers.

For a little historical background on the port numbers, I found this (as one of many) article on the mailgun blog.

Answer 2

I encounter same error message while trying to send email via similar web framework (web2py) and a different email service provider (gmail).

Regardless of the different software components and different email servers, the solution are the same: double check the port of the email service you plan to use. For example, Gmail uses port 465 for SSL, but port 586 for TLS . After I get this right, the email can be sent as expected.