application:__init__.py

from blueprint import example
from extensions import mail
from flask import Flask
import settings


def create_app(settings=settings):
    ret_val = Flask(__name__)
    ret_val.config.from_object(settings)
    # initialize extensions...
    mail.init_app(ret_val)
    # register blueprints...
    ret_val.register_blueprint(example)

    return ret_val

application:blueprint.py

from flask import Blueprint
from tasks import handle_notification


example = Blueprint("example", __name__)


@example.route('/')
def notify():
    ret_val = "Hello World!"
    handle_notification.apply_async([ret_val])

    return ret_val

application:celery.py

from __future__ import absolute_import
from application import settings
from celery import Celery


celery = Celery()
celery.config_from_object(settings)

application:extensions.py

from flask.ext.mail import Mail


mail = Mail()

application:settings.py

BROKER_TRANSPORT = "mongodb"  # ...or your broker of choice.
DEBUG = True

application:tasks.py

from celery import celery
from extensions import mail
from flask.ext.mail import Message


@celery.task
def handle_notification(body):
    message = Message("Test")
    message.body = body

    with mail.connect() as connection:
        connection.send(message)

run.py

from application import create_app


application = create_app()
application.run()