用python自动发送邮件（139邮箱——qq邮箱）报错 求解

源代码如下：

import smtplibfrom email.mime.text import MIMETextfrom email.utils import formataddrfrom email.header import Header# 邮箱配置msg = MIMEText('hello world', 'plain', 'utf-8')msg['From'] = formataddr((Header('Holmes', 'utf-8').encode(), '***@'))msg['To'] = formataddr((Header('Sherlock', 'utf-8').encode(), '***@'))msg['Subject'] = Header('python', 'utf-8').encode()# 发送邮件server = smtplib.SMTP('', 25)server.login('***@', '*******')server.sendmail('***@', '***@', msg.as_string())server.quit()

报错如下：

Traceback (most recent call last):

smtplib.SMTPDataError: (550, b'********** Mail rejected')

********** 代表的是一段字符