import smtplib

server = smtplib.SMTP() 
smtp.connect(smtp_server) # 发件人邮箱中的SMTP服务器，端口默认是25
server.login(sender, passwd) # 发件人邮箱账号、邮箱授权码
# msg.as_string()中as_string()是将msg(MIMEText或MIMEMultipart对象)变为str。
server.sendmail(sender, receive, msg.as_string()) 
server.quit()

import smtplib
from email.mime.text import MIMEText
smtp = smtplib.SMTP()
smtp.connect('smtp.qq.com')
smtp.login('329999897@qq.com','***授权码***')

msg = MIMEText('这是一封测试邮件', "html", "utf-8") #邮件信息对象
msg['from'] = '329999897@qq.com' # 发送人邮箱
msg['to'] = ‘liusir@qq.com' # 邮件接收人邮箱
msg['subject'] = ‘测试邮件' #邮件主题

smtp.sendmail('329999897@qq.com','liusir@qq.com',msg.as_string())
smtp.quit()