input: 
  from celery import Celery
  from flask_mail import Message
  
  app = Celery('tasks', backend='redis://localhost')
  
  @app.task
  def send_email(recipient_name, recipient_email, subject, message):
      """ Create a Celery task in Python to send an email.
      >>> send_email('John Smith', 'john@example.com', 'Hello World', 'This is a test email.')
  
output:     from flask import Flask
      from flask_mail import Mail
  
      flask_app = Flask(__name__)
      flask_app.config['MAIL_SERVER'] = 'smtp.example.com'
      flask_app.config['MAIL_PORT'] = 587
      flask_app.config['MAIL_USE_TLS'] = True
      flask_app.config['MAIL_USERNAME'] = 'your_email@example.com'
      flask_app.config['MAIL_PASSWORD'] = 'your_password'
      mail = Mail(flask_app)
  
      with flask_app.app_context():
          msg = Message(subject, sender='your_email@example.com', recipients=[recipient_email])
          msg.body = f"Dear {recipient_name},\n\n{message}"
          mail.send(msg)