django-ses module not working: Connect timeout when using django.core.mail

Question

I am using django-ses==3.4.1 to send email via django.core.mail and both send_mail() and EmailMessage() get the connection timeout after one minute:

botocore.exceptions.ConnectTimeoutError: Connect timeout on endpoint URL: "https://email-smtp.eu-central-1.amazonaws.com/

Using this configuration in settings.py according to the instructions on https://pypi.org/project/django-ses/

EMAIL_BACKEND = 'django_ses.SESBackend'
AWS_SES_USER = 'my-verified@email'
AWS_SES_ACCESS_KEY_ID = '-my-access-key-'
AWS_SES_SECRET_ACCESS_KEY = '-my-secret-access-key-'
AWS_SES_REGION_NAME = 'eu-central-1'
AWS_SES_REGION_ENDPOINT = 'email-smtp.eu-central-1.amazonaws.com'

Where I use the variable AWS_SES_USER as from_email while calling

email = EmailMessage(subject, message, from_email, recipient_list)
email.content_subtype = 'html'
email.send()

I have also tested if the SES works without Django, i.e. simply using smtplib and it does.

The working example derived from https://realpython.com/python-send-email/#option-2-using-starttls

smtp_server = "email-smtp.eu-central-1.amazonaws.com"
port = 587

# Create a secure SSL context
context = ssl.create_default_context()
# Try to log in to server and send email
try:
    server = smtplib.SMTP(smtp_server,port)
    server.ehlo() # Can be omitted
    server.starttls(context=context) # Secure the connection
    server.ehlo() # Can be omitted
    server.login(AWS_SES_ACCESS_KEY_ID, AWS_SES_SECRET_ACCESS_KEY)
    
    message = """\
Subject: Test SES

This message is sent from Python."""

    receiver_email = 'my-recipient@email'
    server.sendmail(AWS_SES_USER, receiver_email, message)

I have tried changing the parameters in settings.py in many ways, but without success.

Answer 1

Eventually, the working solution without django-ses is simple. However, you have to replace the EmailMessage() with your own function containing the working example mentioned in the question.

Include the following in settings.py:

EMAIL_BACKEND = 'django_ses.SESBackend'
EMAIL_PORT = 587 # TLS=587, SSL=465
AWS_SES_USER = 'my-verified@email'
AWS_SES_ACCESS_KEY_ID = '-my-access-key-'
AWS_SES_SECRET_ACCESS_KEY = '-my-secret-access-key-'
AWS_SES_REGION_NAME = 'eu-central-1'
AWS_SES_REGION_ENDPOINT = 'email-smtp.eu-central-1.amazonaws.com'

Then, you write the send_mail_ses() function in a file (e.g. emailer.py) that you will call from your view (e.g. from views.py):

from django.conf.settings import EMAIL_BACKEND, EMAIL_PORT, \
    AWS_SES_USER, AWS_SES_ACCESS_KEY_ID, \
    AWS_SES_REGION_ENDPOINT, \
    AWS_SES_SECRET_ACCESS_KEY

def send_mail_ses(request, data):
    message = MIMEMultipart("alternative")
    message["Subject"] = data['subject']
    message["From"] = data.get('from', AWS_SES_USER)
    message["To"] = data.get('to')

    part = MIMEText(data['message'], data['how'])    
    message.attach(part)

    context = ssl.create_default_context()
    try:
        server = smtplib.SMTP(AWS_SES_REGION_ENDPOINT, EMAIL_PORT)
        server.ehlo() # Can be omitted
        server.starttls(context=context) # Secure the connection
        server.ehlo() # Can be omitted
        server.login(AWS_SES_ACCESS_KEY_ID, AWS_SES_SECRET_ACCESS_KEY)
        receiver_email = message["To"]
        server.sendmail(
            AWS_SES_USER, receiver_email, message.as_string()
        )
        server.quit()
        return HttpResponse(status=204)
    except Exception as err:
        server.quit() # handle failure
        return HttpResponse(status=500)

Note that you can handle the HttpResponse and any errors as you prefer.

Then, you have two options for formatting the message before sending: plain or html.

With the plain text, you define the data dictionary and pass it to the send_mail_ses() function:

message = "This is the email message."
data = {
    'how': 'plain',
    'subject': f"This is the subject",
    'message': message_text,
    'from': AWS_SES_USER,
    'to': '[email protected]',
}
send_mail_ses(request, data)

With the html formatted:

context = {'message_text': message_text}
html_message = render_to_string("email_template.html", context)
data = {
    'how': 'html',
    'subject': f"This is the subject",
    'message': html_message,
    'from': AWS_SES_USER,
    'to': '[email protected]',
}

send_mail_ses(request, data)

In this case you will have to inject the {{message_text}} from the context into the email_template.html template.

Note: this is untested because it is an extract out of my much more complex code.