smtplib.SMTPServerDisconnected after sending multiple mails in Django

Question

I have a blog post objects. After blog post created I have a signal to dispatch emails. And I want to send emails to multiple subscribers. I am using google mail as a mail server. I put in my settings file some attributes for using mail:

EMAIL_HOST = settings['EMAIL']['HOST']
EMAIL_PORT = settings['EMAIL']['PORT']
EMAIL_HOST_USER = settings['EMAIL']['USER']
EMAIL_HOST_PASSWORD = settings['EMAIL']['PASSWORD']
EMAIL_USE_TLS = True

And function to dispatch mails. Function is a celery task.

@shared_task
def email_dispatch(heading, text):
    recipients = TheUser.objects.filter(subscription=True)

    for recipient in recipients:
        try:
            html_content = render_to_string('mails/email_dispatch.html', {'text': text})
            text_content = strip_tags(html_content)
            subject = '{}'.format(heading)

            email = EmailMultiAlternatives(subject, text_content, to=[recipient.id_user.email])
            email.attach_alternative(html_content, 'text/html')
            email.send()

            logger.info('Successful processed "{}", sent to: "{}"'.format(count_processed, recipient.id_user.username))

        except NoReverseMatch:
            logger.info('Unexpected username: "{}"'.format(recipient.id_user.username))

    logger.info('Email dispatching has been finished.')

At a first glance, all work okay. When celery task starts executing it dispatches correctly. But after approximately sent ~80 emails I receive

smtplib.SMTPServerDisconnected: Connection unexpectedly closed

Unfortunately, I didn't found any info about Google Mail restrictions in that case. Maybe I am setting something wrong from Django side or using an incorrect function for this case.

Thank you for any help.