According to the online tutorial for sending emails in python3, when running in jupyter, a message of failure to send is returned. Is there any missing environment?

The code should be fine, but I’ll post it anyway:

# import smtplib # from email.mime.text import MIMEText # from email.header import Header # # 第三方 SMTP 服务 # mail_host="smtp.qq.com" #设置服务器 # mail_user="我的邮箱" #用户名 # mail_pass="邮箱口令" #口令 # sender = '我的邮箱' # receivers = ['目标邮箱'] # 接收邮件，可设置为你的QQ邮箱或者其他邮箱 # # 三个参数：第一个为文本内容，第二个 plain 设置文本格式，第三个 utf-8 设置编码 # message = MIMEText('这是一个礼物，我等会会删掉的', 'plain', 'utf-8') # message['From'] = Header("你的邮件", 'utf-8') # message['To'] = Header("你的邮件", 'utf-8') # subject = '你的邮件' # message['Subject'] = Header(subject, 'utf-8') # try: # smtpObj = smtplib.SMTP("smtp.qq.com") # smtpObj.connect("smtp.qq.com", 25) # 25 为 SMTP 端口号 # smtpObj.login(mail_user,mail_pass) # smtpObj.sendmail(sender, receivers, message.as_string()) # print ("邮件发送成功") # except smtplib.SMTPException: # print("Error: 无法发送邮件")