Sending mail using flask + blueprint - flask

Question

I have a question about the structure of blueprint
My flask structure looks like
app/
main/
__init__.py
mail.py
__init.py
manage.py
config.py
I register blueprint in __init__.py, for app/__init__.py
from flask_mail import Mail
from flask import Flask
mail = Mail()
def create_app(config_name='develop'):
app = Flask(__name__)
from config import cfg # load EMAIL config from config.py
app.config.from_object(cfg[config_name])
cfg[config_name].init_app(app)
from .main import main # register blueprint
app.register_blueprint(main)
mail.init_app(app) # load related mail config???
return app
Put configs in config.py
class Config():
MAIL_SERVER='<My e-mail SMTP>'
MAIL_DEFAULT_SENDER=('TOPIC', 'mailID')
MAIL_USERNAME='<EMail>'
MAIL_PASSWORD='<EMail Password>'
It returns smtplib.SMTPSenderRefused error when I write codes like this in app/main/mail.py
#main.route('/mail')
def sendmail():
receivers = ['<Receiver 1>', '<Receiver 2>']
app = current_app._get_current_object() # <class 'flask.app.Flask>
mail = Mail(app)
with mail.connect() as conn:
for receiver in receivers:
msg = Message(
subject='subject test',
recipients=[receiver],
html='<h1>Hi~~</h1>')
mail.send(msg)
return 'ok'
It raise a 553 error
smtplib.SMTPSenderRefused: (553, b'Domain name required.', '=?utf-8?q?<TOPIC>?= <mailID>')
I did load config in app/__init__.py, but why I couldn't find MAIL_SERVER and related config in app/main/mail.py?
But if I reload config again in app/main/mail.py, it sends mail successfully
app.config.update(
MAIL_SERVER='<SMTP>',
MAIL_DEFAULT_SENDER=('<TOPIC>', 'mailID'),
MAIL_USERNAME='<email>',
MAIL_PASSWORD='<PASSWORD>'
)
I don't know why I have to do it twice

Answer 1

You should use app_context() like this:
from flask import current_app
from flask_mail import Message, Mail
with current_app.app_context():
mail = Mail()
mail.send(msg)
more info https://flask.palletsprojects.com/en/1.1.x/extensiondev/

Answer 2

The following code is render HTML template for sending mail body including styles or formatted HTML.
from <project-module> import mail
token = user.get_reset_token()
msg = Message('Password Reset Request', sender='<sender-mail>', recipients=[user.email])
msg.html = render_template('email_templates/password_reset.html',
home_link=url_for('home.index', _external=True),
reset_link=url_for(
'account.reset_token', token=token, _external=True),
name=user.name,
email=user.email)
mail.send(msg)
As you mentioned above code. I have been twice initialize Mail object, which is un-necessary.
#main.route('/mail')
def sendmail():
receivers = ['<Receiver 1>', '<Receiver 2>']
mail = Mail()
with mail.connect() as conn:
for receiver in receivers:
msg = Message(
subject='subject test',
recipients=[receiver],
html='<h1>Hi~~</h1>')
mail.send(msg)
return 'ok'

Answer 3

Not a direct answer to your question, but actually I don't think you need to initialize the mail twice.
If you would initialize the mail in app/main/mail.py, there's no point having mail.init_app(app) in app/__init__.py because you never imported it.
Otherwise, in app/main/mail.py I would do import app.mail without creating another mail so that you won't have this config issue in the first place.