django send email using SMTP mail server including no module names 'django_smtp_ssl.

 django, write send email with scheduled times like cron :

https://stackoverflow.com/questions/63552113/gmail-schedule-send-email-in-django

EMAIL_BACKEND = 'django_smtp_ssl.SSLEmailBackend'
EMAIL_USE_TLS = True
EMAIL_HOST = 'smtp.gmail.com'
EMAIL_HOST_USER = 'your_email'
EMAIL_HOST_PASSWORD = 'your password'
DEFAULT_FROM_EMAIL = EMAIL_HOST_USER
EMAIL_PORT = 465

Then in your tasks.py you can add the function for scheduling emails as follows:

from django.template.loader import render_to_string
from django.core.mail import EmailMessage


@periodic_task(
run_every=(crontab(hour=3, minute=34)), #runs exactly at 3:34am every day
name="Dispatch_scheduled_mail",
reject_on_worker_lost=True,
ignore_result=True)
def schedule_mail():
    message = render_to_string('app/schedule_mail.html')
    mail_subject = 'Scheduled Email'
    to_email = getmail
    email = EmailMessage(mail_subject, message, to=[to_email])
    email.send()

django send email offical documentation: 

https://docs.djangoproject.com/en/4.1/topics/email/

Mail is sent using the SMTP host and port specified in the EMAIL_HOST and EMAIL_PORT settings. The EMAIL_HOST_USER and EMAIL_HOST_PASSWORD settings, if set, are used to authenticate to the SMTP server, and the EMAIL_USE_TLS and EMAIL_USE_SSL settings control whether a secure connection is used.

django ModuleNotFoundError: No module named 'django_smtp_ssl'
https://stackoverflow.com/questions/45817296/django-1-8-6-modulenotfounderror-no-module-named-django-smtp-ssl

pip install django-smtp-ssl

For docker, add this in requirements.txt
django-smtp-ssl>=1.0,<2.0
https://pypi.org/project/django-smtp-ssl/#history

post fix admin docker compose set up with mail server

 post fix admin is a management of domain and mail boxes, it needs a mail server to work : 

https://linuxize.com/post/set-up-an-email-server-with-postfixadmin/

before begin, its important to set up MX record for desired mail server at DNS level :

• A record, to point your system’s FQDN (hostname) to your mail server IPv4 address.

mail.linuxize.com. 3600 IN A   23.45.67.89

The FQDN consists of two parts, the hostname and the domain name.

• MX record, to specify which mail server is responsible for accepting email messages on behalf of a recipient’s domain. In our case we want all emails sent to @linuxize.com email addresses to be accepted by the mail.linuxize.com mail server.

linuxize.com.      3600 IN MX  0 mail.linuxize.com.

• SPF record, which is used to verify which mail servers are approved to send email on behalf of a given domain. In the example below we are approving the domain mail servers (mx) and if the SPF check fails, the result will be a soft failure (~all):

linuxize.com.      3600 IN TXT "v=spf1 mx ~all"

set up mail server with docker mail server

 docker mail server :

https://github.com/docker-mailserver/docker-mailserver

guide :

https://betterprogramming.pub/how-to-set-up-a-mailserver-within-a-docker-swarm-e6e9192200c4

Most important thing before starting is to set up mail record for desired domain:

https://linuxize.com/post/set-up-an-email-server-with-postfixadmin/

• A record, to point your system’s FQDN (hostname) to your mail server IPv4 address.

mail.linuxize.com. 3600 IN A   23.45.67.89

The FQDN consists of two parts, the hostname and the domain name.

• MX record, to specify which mail server is responsible for accepting email messages on behalf of a recipient’s domain. In our case we want all emails sent to @linuxize.com email addresses to be accepted by the mail.linuxize.com mail server.

linuxize.com.      3600 IN MX  0 mail.linuxize.com.

• SPF record, which is used to verify which mail servers are approved to send email on behalf of a given domain. In the example below we are approving the domain mail servers (mx) and if the SPF check fails, the result will be a soft failure (~all):

linuxize.com.      3600 IN TXT "v=spf1 mx ~all"