当尝试使用Python发送电子邮件时，解决AttributeError吗？

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

# 设置邮件服务器的相关信息
mail_host = "smtp.exmail.qq.com"
mail_port = 465
mail_user = "your_username"
mail_password = "your_password"

# 设置发件人、收件人、主题和正文
sender = "sender@example.com"
receiver = "receiver@example.com"
subject = "Test Email"
content = "This is a test email."

# 创建邮件对象
message = MIMEText(content, 'plain', 'utf-8')
message['From'] = Header(sender, 'utf-8')
message['To'] = Header(receiver, 'utf-8')
message['Subject'] = Header(subject, 'utf-8')

try:
    # 连接邮件服务器并登录
    smtpObj = smtplib.SMTP_SSL(mail_host, mail_port)
    smtpObj.login(mail_user, mail_password)

    # 发送邮件
    smtpObj.sendmail(sender, receiver, message.as_string())
    print("邮件发送成功")
except smtplib.SMTPException as e:
    print("邮件发送失败：" + str(e))