python - 《Flask Web开发》 第六章 电子邮件 在程序中集成发送电子邮件功能疑问

书上第六章电子邮件，其中的“在程序中集成发送电子邮件功能”一届，按照书上的内容修改代码后，运行，页面可以正常出来，但是在表单中填写新名字时，页面就出错了。

cmd中相关错误显示：

File "C:UsersTonglingDesktopwebhello.py", line 78, in index
send_email(app.config['FLASKY_ADMIN'], 'New User', 'mail/new_user', user=user)
File "C:UsersTonglingDesktopwebhello.py", line 108, in send_email
sender=app.config['FLASKY_MAIL_SENDER'], recipients=[to])
KeyError: 'FLASKY_MAIL_SENDER'

hello.py:

from flask_bootstrap import Bootstrap
from flask_script import Manager     #把命令行解析功能添加到hello.py中
from flask import Flask
from flask import render_template
from flask_moment import Moment
from flask_wtf import FlaskForm
from wtforms import StringField, SubmitField
from wtforms.validators import Required
from datetime import datetime
from flask import session
from flask import redirect
from flask import url_for
from flask import flash
from flask_sqlalchemy import SQLAlchemy
import os
from flask_script import Shell
from flask_migrate import Migrate, MigrateCommand
from flask_mail import Mail
from flask_mail import Message

basedir = os.path.abspath(os.path.dirname(__file__))

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI']=\
    'sqlite:///' + os.path.join(basedir, 'data.sqlite')
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN']=True
app.config['SECRET_KEY'] = 'hard to guess string'
app.config['MAIL_SERVER'] = 'smtp.qq.com'
app.config['MAIL_PORT'] = 25
app.config['MAIL_USE_TLS'] = True
app.config['MAIL_USERNAME'] = os.environ.get('MAIL_USERNAME')
app.config['MAIL_PASSWORD'] = os.environ.get('MAIL_PASSWORD')
app.config['FLASKY_MAIL_SUBJECT_PREFIX'] = '[Flasky]'
app.config['FLASKy_MAIL_SENDER'] = 'Flasky Admin <111111111@qq.com>'
app.config['FLASKY_ADMIN'] = os.environ.get('FLASKY_ADMIN')

db = SQLAlchemy(app)
mail = Mail(app)
bootstrap = Bootstrap(app)
manager = Manager(app)
migrate = Migrate(app, db)

manager.add_command('db', MigrateCommand)

class Role(db.Model):
    __tablename__='roles'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), unique=True)
    
    
    def __repr__(self):
        return '' % self.name
    users = db.relationship('User', backref='role',lazy='dynamic')

class User(db.Model):
    __tablename__='users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), unique=True, index=True)
    
    def __repr__(self):
        return '' % self.username
    role_id = db.Column(db.Integer, db.ForeignKey('roles.id'))
        
class NameForm(FlaskForm):
    name = StringField('你的名字?', validators=[Required()])
    suibmit = SubmitField('Submit')

@app.route('/', methods=['GET','POST'])
def index():
    form = NameForm()
    if form.validate_on_submit():
        user = User.query.filter_by(username=form.name.data).first()
        if user is None:
            user = User(username = form.name.data)
            db.session.add(user)
            session['known'] = False
            if app.config['FLASKY_ADMIN']:
                send_email(app.config['FLASKY_ADMIN'], 'New User', 'mail/new_user', user=user)
        else:
            session['known'] = True
        #old_name = session.get('name')
        #if old_name is not None and old_name !=form.name.data:
        #    flash('看起来你不是同一个人~')
        session['name'] = form.name.data
        form.name.data=''
        return redirect(url_for('index'))
    return render_template('index.html', form=form, name=session.get('name'), known = session.get('known', False))

@app.route('/user/')
def user(name):
    return render_template('user.html', name=name)

@app.errorhandler(404)
def page_not_found(e):
    return render_template('404.html'), 404

@app.errorhandler(500)
def internal_server_error(e):
    return render_template('500.html'), 500


def make_shell_context():
    return dict(app=app, db=db, User=User, Role=Role)
manager.add_command("shell", Shell(make_context=make_shell_context))

def send_email(to, subject, template, **kwargs):
    msg = Message(app.config['FLASKY_MAIL_SUBJECT_PREFIX'] + subject,
                sender=app.config['FLASKY_MAIL_SENDER'], recipients=[to])
    msg.body = render_template(template + '.txt', **kwargs)
    msg.html = render_template(template + '.html', **kwargs)
    mail.send(msg)

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

if __name__ == '__main__':
    db.create_all()
    manager.run()

相关的环境变量也设置了，但是始终出错！！！！！

求指导？？？？？