使用smtplib模块发送邮件，它对smtp协议进行了简单的封装。
smtp协议的基本命令包括：
HELO 向服务器标识用户身份
MAIL 初始化邮件传输 mail from:
RCPT 标识单个的邮件接收人；常在MAIL命令后面,可有多个rcpt to:
DATA 在单个或多个RCPT命令后,表示所有的邮件接收人已标识,并初始化数据传输,以.结束
VRFY 用于验证指定的用户/邮箱是否存在；由于安全方面的原因,服务器常禁止此命令
EXPN 验证给定的邮箱列表是否存在,扩充邮箱列表,也常被禁用
HELP 查询服务器支持什么命令
NOOP 无操作,服务器应响应OK
QUIT 结束会话
RSET 重置会话,当前传输被取消
MAIL FROM 指定发送者地址
RCPT TO 指明的接收者地址
一般smtp会话有两种方式，一种是邮件直接投递，就是说，比如你要发邮件給zzz@163.com，那就直接连接163.com的邮件服务器，把信投給zzz@163.com; 另一种是验证过后的发信，它的过程是，比如你要发邮件給zzz@163.com，你不是直接投到163.com，而是通过自己在sina.com的另一个邮箱来发。这样就要先连接sina.com的smtp服务器，然后认证，之后在把要发到163.com的信件投到sina.com上，sina.com会帮你把信投递到163.com。
文件形式的邮件
#!/usr/bin/env python3
#coding: utf-8
import smtplib
from email.mime.text import MIMEText
from email.header import Header
sender = '***'
receiver = '***'
subject = 'python email test'
smtpserver = 'smtp.163.com'
username = '***'
password = '***'
msg = MIMEText('你好','text','utf-8')#中文需参数‘utf-8’，单字节字符不需要
msg['Subject'] = Header(subject, 'utf-8')
smtp = smtplib.SMTP()
smtp.connect('smtp.163.com')
smtp.login(username, password)
smtp.sendmail(sender, receiver, msg.as_string())
smtp.quit()
html形式的邮件
#!/usr/bin/env python3
#coding: utf-8
import smtplib
from email.mime.text import MIMEText
sender = '***'
receiver = '***'
subject = 'python email test'
smtpserver = 'smtp.163.com'
username = '***'
password = '***'
msg = MIMEText('<html><h1>你好</h1></html>','html','utf-8')
msg['Subject'] = subject
smtp = smtplib.SMTP()
smtp.connect('smtp.163.com')
smtp.login(username, password)
smtp.sendmail(sender, receiver, msg.as_string())
smtp.quit()
带图片的html形式邮件
#!/usr/bin/env python3
#coding: utf-8
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage
sender = '***'
receiver = '***'
subject = 'python email test'
smtpserver = 'smtp.163.com'
username = '***'
password = '***'
msgRoot = MIMEMultipart('related')
msgRoot['Subject'] = 'test message'
msgText = MIMEText('<b>Some <i>HTML</i> text</b> and an image.<br><img src="cid:image1"><br>good!','html','utf-8')
msgRoot.attach(msgText)
fp = open('h:\\python\\1.jpg', 'rb')
msgImage = MIMEImage(fp.read())
fp.close()
msgImage.add_header('Content-ID', '<image1>')
msgRoot.attach(msgImage)
smtp = smtplib.SMTP()
smtp.connect('smtp.163.com')
smtp.login(username, password)
smtp.sendmail(sender, receiver, msgRoot.as_string())
smtp.quit()
带附件的邮件
#!/usr/bin/env python3
#coding: utf-8
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage
sender = '***'
receiver = '***'
subject = 'python email test'
smtpserver = 'smtp.163.com'
username = '***'
password = '***'
msgRoot = MIMEMultipart('related')
msgRoot['Subject'] = 'test message'
#构造邮件中的附件
att = MIMEText(open('h:\\python\\1.jpg', 'rb').read(), 'base64', 'utf-8')
att["Content-Type"] = 'application/octet-stream'
att["Content-Disposition"] = 'attachment; filename="1.jpg"'
msgRoot.attach(att)
smtp = smtplib.SMTP()
smtp.connect('smtp.163.com')
smtp.login(username, password)
smtp.sendmail(sender, receiver, msgRoot.as_string())
smtp.quit()
群邮件
#!/usr/bin/env python3
#coding: utf-8
import smtplib
from email.mime.text import MIMEText
sender = '***'
receiver = ['***','****',……]
subject = 'python email test'
smtpserver = 'smtp.163.com'
username = '***'
password = '***'
msg = MIMEText('你好','text','utf-8')
msg['Subject'] = subject
smtp = smtplib.SMTP()
smtp.connect('smtp.163.com')
smtp.login(username, password)
smtp.sendmail(sender, receiver, msg.as_string())
smtp.quit()
也可使用yagmail模块来快速实现
实现代码如下：
import yagmail
yag = yagmail.SMTP(user='XXX@gmail.com',password='XXX'
yag.send(to = 'XXX@qq.com',subject ='test',contents = 'This is a test e-mail from Windows CMD tools with the yagmai')
