如何在python中通过sendemail向消息传递字符串

import smtplib
from email.mime.text import MIMEText
from email.header import Header

def send_email(sender, receiver, subject, message):
    # 设置邮件内容
    msg = MIMEText(message, 'plain', 'utf-8')
    msg['From'] = Header(sender, 'utf-8')
    msg['To'] = Header(receiver, 'utf-8')
    msg['Subject'] = Header(subject, 'utf-8')

    # 连接SMTP服务器
    smtp_server = 'smtp.example.com'  # 替换为实际的SMTP服务器地址
    smtp_port = 25  # 替换为实际的SMTP服务器端口号
    smtp_username = 'your_username'  # 替换为实际的SMTP用户名
    smtp_password = 'your_password'  # 替换为实际的SMTP密码
    smtp = smtplib.SMTP(smtp_server, smtp_port)
    smtp.login(smtp_username, smtp_password)

    # 发送邮件
    smtp.sendmail(sender, receiver, msg.as_string())

    # 关闭连接
    smtp.quit()

# 调用函数发送邮件
sender = 'sender@example.com'  # 发件人邮箱
receiver = 'receiver@example.com'  # 收件人邮箱
subject = 'Test Email'  # 邮件主题
message = 'Hello, this is a test email.'  # 邮件内容
send_email(sender, receiver, subject, message)