I'm developing a Flask application that implements a user registration system. The application uses Flask-Mail and itsdangerous to confirm a user's registration and reset their password via email. I configured Flask-Mail to use the recommended server settings provided by the email host that I'm using.
MAIL_PORT = 587
MAIL_USE_SSL = False
MAIL_USE_TLS = True
At first, things were working fine; I could submit emails without any issues. However, seemingly without changing any configuration settings, I now receive the following error when attempting to submit an email using Flask-Mail:
[SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:1123)
I'm not sure where the problem is, and I am wondering if something has changed on the email provider's end? I have tried setting MAIL_PORT = 25 with MAIL_USE_SSL=False and MAIL_USE_TLS=False; and, MAIL_PORT = 465 with MAIL_USE_SSL=True and MAIL_USE_TLS=False as well. Using the former, I receive the same error as with port 587, but using the latter I'm receiving STARTTLS extension not supported by server.
I'm running the Flask app in development mode at localhost:5000. Here's some of my configuration settings and code:
config.py
SECRET_KEY = 'verysecret'
MAIL_SERVER = "smtp.mymailservice.com"
MAIL_PORT = 587
MAIL_USE_SSL = False
MAIL_USE_TLS = True
MAIL_USERNAME = "myemail@myhostname.com"
MAIL_PASSWORD = "mypassword"
MAIL_DEFAULT_SENDER = 'Brand <noreply@myhostname.com>'
app/mailing.py
from flask_mail import Message
from flask import current_app
from .extensions import mail
def send_email(to, subject, template):
msg = Message(
subject,
recipients=[to],
html=template,
sender=current_app.config["MAIL_DEFAULT_SENDER"]
)
mail.send(msg)
app/users/routes.py
(One of the routes where I receive the error)
from flask import (
render_template, session, request, redirect, url_for, g, jsonify, flash
)
import uuid
from passlib.hash import sha256_crypt
from app.mailing import send_email
from app.extensions import db
from app.users import bp
from app.users.forms import *
from app.users.models import *
from app.users.token import *
@bp.route('/register', methods=['POST', 'GET'])
def register():
# Initialize the Register Form
form = RegisterForm()
# If the submitted form is valid
if form.validate_on_submit():
# Check to see if a user already exists with this email address
user = User.query.filter_by(email=form.email.data).first()
# If there is not a user with this email address, create a new user
if not user:
new_user = User(public_id=str(uuid.uuid4()),
email=form.email.data,
password=sha256_crypt.encrypt(
(form.password.data)),
first_name=form.firstname.data,
last_name=form.lastname.data
)
db.session.add(new_user)
db.session.commit()
token = generate_confirmation_token(new_user.email)
confirm_url = url_for("users.confirm_email",
token=token, _external=True)
html = render_template('confirm_email.html',
confirm_url=confirm_url)
subject = "Please confirm your email"
try:
send_email(new_user.email, subject, html)
flash("A confirmation email has been sent to you. Please verify your email address to activate your account.", category="success")
except Exception as e:
flash(
"There was a problem sending the confirmation email. Please try again later.", category="danger")
print(e)
session["user_id"] = new_user.public_id
session["email"] = new_user.email
session["name"] = new_user.first_name
flash("Thanks for registering!", category="success")
return redirect(url_for('users.unconfirmed'))
else:
flash("There is already an account associated with this email address. Log in, or use a different email address.")
return render_template("register_user.html", form=form)
app/extensions.py
from flask_mail import Mail
from flask_bootstrap import Bootstrap
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()
bootstrap = Bootstrap()
mail = Mail()
app/init.py
from flask import Flask
from config import Config, DevelopmentConfig
from .errors import (
page_not_found, forbidden, internal_server_error
)
from .extensions import (
db, mail, bootstrap
)
def create_app(config_class=DevelopmentConfig):
app = MyFlask(__name__)
# Set Configuration
app.config.from_object(config_class)
# Register extensions
# Initialize Boostrap-Flask
bootstrap.init_app(app)
# Initialize Flask-SQLAlchemy
db.init_app(app)
# Initialize Flask-Mail
mail.init_app(app)
# Register error views
app.register_error_handler(404, page_not_found)
app.register_error_handler(403, forbidden)
app.register_error_handler(500, internal_server_error)
with app.app_context():
# register blueprints
from app.main import bp as bp_main
app.register_blueprint(bp_main)
from app.users import bp as bp_users
app.register_blueprint(bp_users)
return app
