Flask-Mail Cannot read configurations when config.from_object() is used

Question

I have two versions of codes for sending emails

Version 1 (W/O external config file)

# app.py
from flask import Flask
from flask_mail import Mail, Message

mail = Mail()

app =Flask(__name__)

app.config['MAIL_SERVER']='smtp.gmail.com'
app.config['MAIL_PORT'] = 465
app.config['MAIL_USERNAME'] = 'test@gmail.com'
app.config['MAIL_PASSWORD'] = 'test'
app.config['MAIL_USE_TLS'] = False
app.config['MAIL_USE_SSL'] = True
print(app.config)
mail.init_app(app)

@app.route("/")
def index():
    msg = Message('Hi', sender = 'test@gmail.com', recipients = ['test@gmail.com'])
    msg.body = "Hello"
    mail.send(msg)
    return "Sent"

if __name__ == '__main__':
    app.run(debug = True)

This version sends emails no problems

Version 2 (Config using from_object())

# app.py
from flask import Flask
from flask_mail import Mail, Message

mail = Mail()

app = Flask(__name__)

app.config.from_object('config.DevelopmentConfig')

# mail = Mail(app)
print(app.config)
mail.init_app(app)

@app.route("/")
def index():
    print('Sending email')
    msg = Message('Tutorial point3', sender = 'test@gmail.com', recipients = ['test@gmail.com'])
    msg.body = "Hello Flask message sent from Flask-Mail "
    mail.send(msg)
    return "Sent"

if __name__ == '__main__':
    app.run()

Below is configuration file

# config.py

class BaseConfig:
    """Base configuration"""
    DEBUG = False
    TESTING = False
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SECRET_KEY = 'my_precious'
    MAIL_SERVER = 'smtp.gmail.com'
    MAIL_PORT = 465
    MAIL_USE_SSL = True
    MAIL_USE_TLS = False
    MAIL_USERNAME = 'test@google.com'
    MAIL_PASSWORD = 'test'


class DevelopmentConfig(BaseConfig):
    """Development configuration"""
    DEBUG = True

Somehow version 2 does not work and give me this error

smtplib.SMTPAuthenticationError: (535, b'5.7.8 Username and Password not accepted. Learn more at\n5.7.8  https://support.google.com/mail/?p=BadCredentials x4sm75923481pfk.51 - gsmtp')

The error message says my credential is wrong but I think that it not true because in version 1 I use exact same username and password and it worked fine.

To find out if my configuration from config.py is loaded, I did print(app.config) (although I am not sure if it was a good way) and it looks like my configuration is correctly loaded to my flask app.

<Config {'DEBUG': True, 'TESTING': False, 'PROPAGATE_EXCEPTIONS': None, 'PRESERVE_CONTEXT_ON_EXCEPTION': None, 'SECRET_KEY': 'my_precious', 'PERMANENT_SESSION_LIFETIME': datetime.timedelta(31), 'USE_X_SENDFILE': False, 'LOGGER_NAME': '__main__', 'LOGGER_HANDLER_POLICY': 'always', 'SERVER_NAME': None, 'APPLICATION_ROOT': None, 'SESSION_COOKIE_NAME': 'session', 'SESSION_COOKIE_DOMAIN': None, 'SESSION_COOKIE_PATH': None, 'SESSION_COOKIE_HTTPONLY': True, 'SESSION_COOKIE_SECURE': False, 'SESSION_REFRESH_EACH_REQUEST': True, 'MAX_CONTENT_LENGTH': None, 'SEND_FILE_MAX_AGE_DEFAULT': datetime.timedelta(0, 43200), 'TRAP_BAD_REQUEST_ERRORS': False, 'TRAP_HTTP_EXCEPTIONS': False, 'EXPLAIN_TEMPLATE_LOADING': False, 'PREFERRED_URL_SCHEME': 'http', 'JSON_AS_ASCII': True, 'JSON_SORT_KEYS': True, 'JSONIFY_PRETTYPRINT_REGULAR': True, 'JSONIFY_MIMETYPE': 'application/json', 'TEMPLATES_AUTO_RELOAD': None, 'MAIL_PASSWORD': 'test', 'MAIL_PORT': 465, 'MAIL_SERVER': 'smtp.gmail.com', 'MAIL_USERNAME': 'test@google.com', 'MAIL_USE_SSL': True, 'MAIL_USE_TLS': False, 'SQLALCHEMY_TRACK_MODIFICATIONS': False}>

Thank you for your help in advance!

Update1: Modify the title for the better understanding. Also when I tested both versions, I used actual gmail address and password, but in the code snippet I replaced all credentials to "test" to protect my account

How did you confirm that version 1 works? Did you actually put in a real email address and receive an email? — Kent Shikama, Dec 30 '17 at 05:47
@kshikama Yes, I created two gmail accounts and I can send with my version 1 code and receive it on my other gmail account. I replace my credentials to "test" in order to protect my password and email address. — ksn, Dec 30 '17 at 05:57
Hi @ksn. The domain for your email in version 2 isn't right. You mean to use `gmail.com` not `google.com` — Oluwafemi Sule, Dec 30 '17 at 09:00
@OluwafemiSule Oh thank you so much. It was from [here] (http://flask.pocoo.org/snippets/85/), and I did not notice the typo. — ksn, Dec 31 '17 at 01:47

score 1 · Accepted Answer · answered Dec 31 '17 at 01:50

There was a typo in the version 2. I copied the code from this flask official snippets, so I hope this answer helps people from falling into the same trap.

class BaseConfig:
    """Base configuration"""
    DEBUG = False
    TESTING = False
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SECRET_KEY = 'my_precious'
    MAIL_SERVER = 'smtp.gmail.com' # <-- Here
    MAIL_PORT = 465
    MAIL_USE_SSL = True
    MAIL_USE_TLS = False
    MAIL_USERNAME = 'test@gmail.com'
    MAIL_PASSWORD = 'test'


class DevelopmentConfig(BaseConfig):
    """Development configuration"""
    DEBUG = True

Flask-Mail Cannot read configurations when config.from_object() is used

1 Answers1