发邮件是一种很常见的操作，本篇主要介绍一下如何用python实现自动发件。

import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.header import Header
from email.mime.image import MIMEImage
import time
mail_host="smtp.126.com"
mail_user="xxx@126.com"
mail_pass="******"#注意如果邮箱开启了授权码，此处要填写授权码，否则会报smtplib.SMTPAuthenticationError: (535, b'Error: authentication failed')
sender="xxx@126.com"
receiver = ['邮箱1','邮箱2']#群发邮件
for i in range(n):#自定义循环发多少遍
	try:
		message = MIMEMultipart()
    	message["From"] = Header(sender)
    	message["To"] = ','.join(receiver)
    	message["Subject"] = Header("主题", "utf-8").encode()#主题
    	message.attach(MIMEText("正文", "plain", "utf-8"))#正文
    	""" 定附件 """
    	att = MIMEText(open(r'C:\Users\Administrator\Desktop\1.txt').read(), "base64", "utf-8")
    	att["Content-Type"] = 'application/octet-stream'
   	 	att.add_header("Content-Disposition", 'attachment', filename="1.txt")#这一步可避免文件不能正常打开
    	message.attach(att)
    	""" 构造图片（以附件形式上传） """
    	image = MIMEImage(open(r'C:\Users\Administrator\Desktop\1.jpg', 'rb').read())
    	image.add_header('Content-ID', '<image1>')#可避免图片不能正常打开
    	image["Content-Disposition"] = 'attachment; filename="picture.jpg"'
    	message.attach(image)
   		""" 发送邮件 """
    	smtp = smtplib.SMTP_SSL(host=mail_host)
    	smtp.connect(host=mail_host, port=465)
    	smtp.login(mail_user, mail_pass)
    	smtp.sendmail(sender, message['To'].split(','), message.as_string())
    	print("在%s第" % ctime(), str(i+1), "封邮件发送")
    	smtp.quit()
	except smtplib.SMTPException as e:
      	raise e

最终实现