域名邮箱验证失败是怎么回事

import smtplib
from email.mime.text import MIMEText

def send_verification_email(to_email, verification_link):
    msg = MIMEText(f'请点击以下链接进行邮箱验证：{verification_link}', 'plain', 'utf-8')
    msg['From'] = 'your_email@example.com'
    msg['To'] = to_email
    msg['Subject'] = '邮箱验证'

    try:
        smtp_server = smtplib.SMTP('smtp.example.com', 25)
        smtp_server.login('your_email@example.com', 'your_password')
        smtp_server.sendmail('your_email@example.com', [to_email], msg.as_string())
        smtp_server.quit()
        print("邮件发送成功")
    except Exception as e:
        print(f"邮件发送失败: {e}")

# 示例调用
send_verification_email('user@example.com', 'https://example.com/verify?token=123456')