Sending welcome emails asynchronously in python Flask application

You can do it with threads as shown in Grinberg's tutorial

from threading import Threaddef threading(f):    def wrapper(*args, **kwargs):        thr = Thread(target=f, args=args, kwargs=kwargs)        thr.start()    return wrapper@threadingdef send_email(subject, to, body, html=None):    def send():        try:            mail.send(msg)        except Exception as err:            app.logger.error("Error during mail send: {0}".format(err))    with app.app_context():        msg = Message(subject, recipients=[to], body=body, html=html,                      sender="welcome@myapp.net")        send()

And then in your view you can call send_email and not have to wait

If you want to incorporate feedback (aka live information in case there's an error when sending the email) for the email, you should add a message broker (i.e rabbitmq, zeromq) and a task queue (i.e celery) to the implementation (and a way to poll asynchronously for messages from the UI). Although I don't think you really need something like this for welcome emails -unless you send them in batches, you can find an example of how to use such stuff here