Django send_mail through gmail very slow

问题

When I try send through ./manage.py shell it takes several minutes to send a single email. When I try to send a user verification email after a form submission in a browser the browser times out with a 504, but the email is eventually sent. What could be going on?

settings.py

...
EMAIL_HOST = 'smtp.gmail.com'                                                   
EMAIL_HOST_USER = 'myemail@gmail.com'                                      
EMAIL_PORT = 587                                                                
EMAIL_USE_TLS = True                                                            
DEFAULT_FROM_EMAIL = EMAIL_HOST_USER                                            
EMAIL_HOST_PASSWORD = os.environ.get('PASSWORD')   
...

views.py

class SignUpView(CreateView):                                                   
    model = User                                                                
    template_name = 'eventMap/register.html'                                    
    form_class = RegistrationForm                                               
    success_url="/"                                                             

    def form_valid(self, form):                                                 
                form.save()                                                     
                username = form.cleaned_data['username']                        
                email = form.cleaned_data['email']                              
                salt = hashlib.sha1(str(random.random())).hexdigest()[:5]          
                activation_key = hashlib.sha1(salt+email).hexdigest()           
                key_expires = datetime.datetime.today() + datetime.timedelta(2) 

                #Get user by username                                           
                user=User.objects.get(username=username)                        

                # Create and save user profile                                  
                new_profile = UserProfile(user=user, activation_key=activation_key,
                        key_expires=key_expires)                                
                new_profile.save()                                              

                # Send email with activation key                                
                email_subject = 'Account confirmation'                          
                email_body = "Hey %s, thanks for signing up. To activate your account, click this link within \
                48hours http://mywebsite.com/accounts/confirm/%s" % (username, activation_key)

                send_mail(email_subject, email_body, 'myemail@gmail.com',  
                        ['mytestemail@gmail.com'], fail_silently=False)   

                return super(SignUpView, self).form_valid(form)

I came across this post about something similar but the logs don't mention anything about an unqualified hostname etc /var/log/mail.log

Jul 27 16:26:04 django postfix/qmgr[5975]: CAF7C1226F2: from=<>, size=3063, nrcpt=1 (queue active)
Jul 27 16:26:34 django postfix/smtp[12874]: connect to example.com[2606:2800:220:1:248:1893:25c8:1946]:25: Connection timed out
Jul 27 16:27:04 django postfix/smtp[12874]: connect to example.com[93.184.216.34]:25: Connection timed out
Jul 27 16:27:04 django postfix/smtp[12874]: CAF7C1226F2: to=<myemail@example.com>, relay=none, delay=368178, delays=368118/0.02/60/0, dsn=4.4.1, status=deferred (connect to example.com[93.184.216.34]:25: Connection timed out)

回答1:

I had a similar case where the delay and timeout were caused by the system trying to connect to gmail over IPv6.

This thread was useful in uncovering the mystery.

TLDR:

On the host machine try using telnet to connect to gmail.

telnet smtp.gmail.com 587

If it first attempts to connect over IPv6 (and blocks for a few minutes) followed by a successful connection on IPv4, then this is likely your problem.

The solution:

import socket
EMAIL_HOST = socket.gethostbyname('smtp.gmail.com')

This ensures that python will connect to gmail over IPv4 from the beginning.

Better solution:

Figure out why your host can't connect to gmail over IPv6 and fix that issue. Perhaps adjusting firewall rules to reject packets instead of dropping them.

回答2:

For me, Email is hosted on ScalaHosting. Testing connection using telenet showed that port 26 is very fast. Before I used port 25 which was very slow.

I suggest to test your SMTP server using telnet to choose the correct and fast port.

Example:

telnet mx-s2.vivawebhost.com 26

回答3:

You might not want to send emails through gmail. It's not really the intended use for a standard smtp service like Gmail.

Have you tried configuring your email notifications to run through a mail distribution service like Mandrill to start off with?

There are a few Django apps such as Djrill that "just work" using the standard Django email functions such as send_mail().

来源：https://stackoverflow.com/questions/31663454/django-send-mail-through-gmail-very-slow

标签

python

django

smtp

gmail