Flask异步发送邮件

from flask import Flask
from flask.ext.mail import Mail, Message
from threading import Thread

app = Flask(__name__)

app.config.update(dict(
    MAIL_SERVER='smtp.qq.com',
    MAIL_PORT=587,
    MAIL_USE_TLS=True,
    MAIL_USERNAME = 'xxx@qq.com', #use to send email
    MAIL_PASSWORD='yyy' #password
))

mail = Mail(app)

def send_async_email(msg):
    with app.app_context():
        mail.send(msg)

def send_email():
    msg = Message('Hello, World!', #主题
　  sender=app.config['MAIL_USERNAME'],  #发件人
　  recipients=['zzz@163.com'] #收件人
    )
    msg.body = "Hello" #纯文本正文
    msg.html = "World" #富文本正文（测试时邮件显示这个内容）
    thr = Thread(target=send_async_email, args=[msg])
    thr.start()
    return thr   

@app.route('/')
def index():
    send_email()
    return '<h1>Hello,World!</h1>'

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