python3.x实现自动发送邮件

#!/bin/python
#coding=utf-8
#导入smtplib和MIMEText
import smtplib
from email.mime.text import MIMEText
#############
#要发给谁
mailto_list=["418626307@qq.com"]
#####################
#设置发送邮箱的服务器，用户名、口令以及邮箱的后缀
mail_host="smtp.139.com"
mail_user="xxxxxxx"     #用户名
mail_pass="xxxxxxxx"    #密码
mail_postfix="139.com"
######################
def send_mail(to_list,sub,content):
'''
to_list:发给谁
sub:主题
content:内容
send_mail("aaa@163.com","sub","content")
'''
me=mail_user+"<"+mail_user+"@"+mail_postfix+">"
msg = MIMEText(content)
msg['Subject'] = sub
msg['From'] = me
msg['To'] = ";".join(to_list)

try:
s = smtplib.SMTP()
s.connect(mail_host)
s.login(mail_user,mail_pass)
s.sendmail(me, to_list, msg.as_string())
s.close()
return True
except Exception as e :
print(str(e))
return False

if __name__ == '__main__':
if send_mail(mailto_list,"这是一封测试邮件的标题","这是一封测试邮件的内容"):
print ("发送成功")
else:
print ("发送失败")