python发邮件出现smtplib.SMTPServerDisconnected: Connection unexpectedly closed问题的解决办法

#coding: utf-8
import smtplib
from email.mime.text import MIMEText
from email.header import Header

#收件人和发件人
receiver = '[email protected]'
sender = '[email protected]'

#发件人邮箱的SMTP服务器（即sender的SMTP服务器）
smtpserver = 'smtp.qq.com'

#发件人邮箱的用户名和授权码（不是登陆邮箱的密码）
username = '[email protected]'
password = 'moxxxxxxxxxxxfcd'       #（[email protected]邮箱的授权码）

mail_title = '有陌生人来访！'
mail_body = '请查看附件图片'

#创建一个实例
message = MIMEText( mail_body, 'plain', 'utf-8' )   #邮件正文
# (plain表示mail_body的内容直接显示，也可以用text，则mail_body的内容在正文中以文本的形式显示，需要下载）
message ['From'] = sender                                               #邮件上显示的发件人
message['To'] = receiver                                                   #邮件上显示的收件人
message['Subject'] = Header( mail_title, 'utf-8' )   #邮件主题

smtp = smtplib.SMTP()                                                     #创建一个连接
smtp.connect( smtpserver )                                            #连接发送邮件的服务器
smtp.login( username, password )                                #登录服务器
smtp.sendmail( sender, receiver, message.as_string() )      #填入邮件的相关信息并发送
smtp.quit()

运行结果：

D:\Python\python3.exe "D:/PyCharm files/face/raspberry/smtp.py"
Traceback (most recent call last):
  File "D:/PyCharm files/face/raspberry/smtp.py", line 43, in <module>
    smtp.login( username, password )                                #登录服务器
  File "D:\Python\lib\smtplib.py", line 721, in login
    initial_response_ok=initial_response_ok)
  File "D:\Python\lib\smtplib.py", line 631, in auth
    (code, resp) = self.docmd("AUTH", mechanism + " " + response)
  File "D:\Python\lib\smtplib.py", line 421, in docmd
    return self.getreply()
  File "D:\Python\lib\smtplib.py", line 394, in getreply
    raise SMTPServerDisconnected("Connection unexpectedly closed")

smtplib.SMTPServerDisconnected: Connection unexpectedly closed

解决方案：

在smtp.login(username,password)前面添加两行代码，即可实现邮件成功发送。添加的代码如下：

smtp.ehlo()
smtp.starttls()