How to do scheduled sending of email with django-mailer

Question

Hi,

I'm making a django app that needs to be able to make emails and then send these out at a given time. I was thinking i could use django-mailer to put things in que and then send it of. But even though theire sample case list, lists that this is a feature, I cant seem to find out how.

What I need is to be able to set a 'when_to_send' field in the message model of django-mailer, and when the cron job fires the send_mail function this needs to filter out the ones that has a 'when_to_send' date that is greater than the current time...

def send_all():
    """
    Send all eligible messages in the queue.
    """

    lock = FileLock("send_mail")

    logging.debug("acquiring lock...")
    try:
        lock.acquire(LOCK_WAIT_TIMEOUT)
    except AlreadyLocked:
        logging.debug("lock already in place. quitting.")
        return
    except LockTimeout:
        logging.debug("waiting for the lock timed out. quitting.")
        return
    logging.debug("acquired.")

    start_time = time.time()

    dont_send = 0
    deferred = 0
    sent = 0

    try:
        for message in prioritize():
            if DontSendEntry.objects.has_address(message.to_address):
                logging.info("skipping email to %s as on don't send list " % message.to_address)
                MessageLog.objects.log(message, 2) # @@@ avoid using literal result code
                message.delete()
                dont_send += 1
            else:
                try:
                    logging.info("sending message '%s' to %s" % (message.subject.encode("utf-8"), message.to_address.encode("utf-8")))
                    core_send_mail(message.subject, message.message_body, message.from_address, [message.to_address])
                    MessageLog.objects.log(message, 1) # @@@ avoid using literal result code
                    message.delete()
                    sent += 1
                except (socket_error, smtplib.SMTPSenderRefused, smtplib.SMTPRecipientsRefused, smtplib.SMTPAuthenticationError), err:
                    message.defer()
                    logging.info("message deferred due to failure: %s" % err)
                    MessageLog.objects.log(message, 3, log_message=str(err)) # @@@ avoid using literal result code
                    deferred += 1
    finally:
        logging.debug("releasing lock...")
        lock.release()
        logging.debug("released.")

    logging.info("")
    logging.info("%s sent; %s deferred; %s don't send" % (sent, deferred, dont_send))
    logging.info("done in %.2f seconds" % (time.time() - start_time))

Anyone see how to customize this function to don't send email's where the message.when_to_send field is greater than the current time?

Answer 1

You can just add another clause to the conditionals under your message processing loop (you will also need to import datetime at the top of your file):

         for message in prioritize():
            if DontSendEntry.objects.has_address(message.to_address):
                logging.info("skipping email to %s as on don't send list " % message.to_address)
                MessageLog.objects.log(message, 2) # @@@ avoid using literal result code
                message.delete()
                dont_send += 1
            elif message.when_to_send > datetime.datetime.now():
                continue
            else:
                try:
                  ... the rest of your code ...

Answer 2

You need to implement the cron job for django-mailer:

* * * * * (cd $PINAX; /usr/local/bin/python2.5 manage.py send_mail >> $PINAX/cron_mail.log 2>&1)

And then in engine.py line 96:

   # Get rid of "while True:"
   while not Message.objects.all():
        # Get rid of logging.debug("sleeping for %s seconds before checking queue again" % EMPTY_QUEUE_SLEEP)
        # Get rid of sleep
        send_all()