# 建立会话

S: 220 smtp.example.com ESMTP Postfix

C: HELO client.example.org

S: 250 Hello client.example.org, I am glad to meet you

# 发送消息

C: MAIL FROM:<sender@example.org>

S: 250 Ok

C: RCPT TO:<receiver1@example.com>

S: 250 Ok

C: RCPT TO:<receiver2@example.com>

S: 250 Ok

C: DATA

S: 354 End data with <CR><LF>.<CR><LF>

C: From: "Sender Example" <sender@example.org>

C: To: "Receiver1 Example" <receiver1@example.com>

C: Cc: receiver2@example.com

C: Date: Tue, 15 January 2008 16:02:43 -0500

C: Subject: Test message

C:

C: Hello Receiver1.

C: This is a test message with 5 header fields and 4 lines in the message body.

C: Your friend,

C: Sender

C: .

S: 250 Ok: queued as 12345

C: QUIT

S: 221 Bye

{The server closes the connection}

C: HELO client.example.org --- SMTP.helo([hostname]): 使用HELO向SMTP服务器标识自己。

S: 250 Hello client.example.org, I am glad to meet you

 --- SMTP.verify(address)：服务器用来验证地址的有效性，返回一个元组（250，相关地址）或者（>=400, 错误消息字符串）。

C: MAIL FROM:<sender@example.org> --- low-level methods: mail()

C: RCPT TO:<receiver1@example.com> --- low-level methods: rcpt()

C: DATA --- low-level methods: data()

C: QUIT --- SMTP.quit(): 终止会话，关闭连接。

 # -*- coding:utf-8 -*-

 from __future__ import print_function

 from __future__ import with_statement

 __author__ = 'xxx'

 __all__ = ['BTEmail']

 import smtplib

 import sys

 import os

 import time

 import mimetypes

 from email import encoders

 from email.header import Header

 from email.utils import parseaddr, formataddr

 from email.mime.text import MIMEText

 from email.mime.multipart import MIMEMultipart

 from email.mime.image import MIMEImage

 from email.mime.audio import MIMEAudio

 from email.mime.base import MIMEBase

 # ----- The following information should be in the configuration file.

 from_addr = 'xxx@sina.com'

 to_addrs = ['yyy@126.com',  'zzz@163.com']

 cc_addrs = ['xxx@sina.com', 'www@qq.com']

 bcc_addrs = []

 username = 'xxx@sina.com'

 password = '---'

 # ------------------------------------------------------------------------------------

 class BTEmail(object):

     def __init__(self, host='smtp.sina.com', port=465, username=None, password=None):

         self.host = host

         self.port = port

         self.username = username

         self.password = password

     @classmethod

     def _format_addr(cls, envolope_string):

         # parseaddr() only parses single address or string.

         (name, addr) = parseaddr(envolope_string)

         return formataddr((\

             Header(name, 'utf-8').encode(),\

             addr.encode('utf-8') if isinstance(addr, unicode) else addr))

     @classmethod

     def construct_msg(cls, contentfile, contenttype='html', charset='utf-8', 
　　　　　　　　　　　　　　　　　　attach_flag=False, attachpath=None):

         with open(contentfile, 'rb') as fp:

             content = MIMEText(fp.read(), contenttype, charset)

         if not attach_flag:

             msg = content

         else:

             # Construct root container.

             msg = MIMEMultipart()

             # Attach mail contents to the container.

             msg.attach(content)

             # Attach attachments to the container.

             for filename in os.listdir(attachpath):

                 item = os.path.join(attachpath, filename)

                 if not os.path.isfile(item):

                     continue

                 #  Guess the content type based on the file's extension.

                 (ctype, encoding) = mimetypes.guess_type(item)

                 if ctype is None or encoding is not None:

                     ctype = 'application/octet-stream'

                 (maintype, subtype) = ctype.split('/', 1)

                 # Load  and encode attachments.

                 """

                 # Use MIMEBase class construct attachments.

                 with open(item, 'rb') as fp:

                     attachment = MIMEBase(_maintype=maintype, _subtype=subtype)

                     attachment.set_payload(fp.read())

                     encoders.encode_base64(attachment)

                 """

                 # Use concrete type class construct attachments.

                 if maintype == 'text':

                     with open(item, 'rb') as fp:

                         attachment = MIMEText(fp.read(), _subtype=subtype)

                 elif maintype == 'image':

                     with open(item, 'rb') as fp:

                         attachment = MIMEImage(fp.read(), _subtype=subtype)

                 elif maintype == 'audio':

                     with open(item, 'rb') as fp:

                         attachment = MIMEAudio(fp.read(), _subtype=subtype)

                 else:

                     with open(item, 'rb') as fp:

                         attachment = MIMEBase(_maintype=maintype, _subtype=subtype)

                         attachment.set_payload(fp.read())

                         encoders.encode_base64(attachment)

                 # Set attachment header.

                 attachment.add_header('Content-Disposition', 'attachment', filename=filename)

                 msg.attach(attachment)

         return msg

     @classmethod

     def make_envolope(cls, msg, from_addr, to_addrs, subject='A Simple SMTP Demo'):

         if msg:

             msg['From'] = cls._format_addr(u'BT<%s>' % from_addr)

             # msg['To'] should be a string, not a list.

             msg['To'] = ','.join(to_addrs)

             msg['Cc'] = ','.join(cc_addrs)

             msg['Bcc'] = ','.join(bcc_addrs)

             msg['Subject'] = Header(u'主题<%s>' % subject, 'utf-8').encode()

     def send_mail(self, from_addr, to_addrs, msg):

         smtp_server = smtplib.SMTP_SSL()

         try:

             #smtp_server.set_debuglevel(True)

             RECONNECT = 10      # Reconnect times.

             for i in xrange(RECONNECT):

                 try:

                     smtp_server.connect(self.host, self.port)

                 except smtplib.SMTPConnectError:

                     if i < RECONNECT:

                         print('Connecting to smtp server...')

                         time.sleep(6)

                         continue

                     else:

                         sys.exit('Can not connect to smtp server.')

                 except smtplib.SMTPServerDisconnected:

                     sys.exit('SMTP server is lost.')

                 else:

                     break

             try:

                 smtp_server.starttls()

             except smtplib.SMTPException:

                 print('SMTP server does not support the STARTTLS extension.')

             try:

                 smtp_server.login(username, password)

             except smtplib.SMTPAuthenticationError:

                 print('Username or Password is incorrect.')

             try:

                 refusal_dict = smtp_server.sendmail(from_addr,  to_addrs, msg.as_string())

             except smtplib.SMTPSenderRefused:

                 sys.exit('SMTP server does not accept the %s.' % from_addr)

             except smtplib.SMTPDataError:

                 sys.exit('SMTP server replied with an unexpected error code .')

             else:

                 if refusal_dict:

                     print('*****SMTP server rejects the following recipients:*****')

                     print(list(refusal_dict.items()))

                     print('*******************************************************')

         finally:

             smtp_server.quit()

 def main():

     # Send text/plain email.

     """

     email_obj = BTEmail(host='smtp.sina.com', port=465, username=username, password=password)

     msg = email_obj.construct_msg(r'content\mail.txt', 'plain', 'utf-8')

     email_obj.make_envolope(msg, from_addr, to_addrs, subject='This is a plain text mail.')

     email_obj.send_mail(from_addr, to_addrs + cc_addrs, msg)

     """

     # Send text/html email.

     """

     email_obj = BTEmail(host='smtp.sina.com', port=465, username=username, password=password)

     msg = email_obj.construct_msg(r'content\mail.html', 'html', 'utf-8')

     email_obj.make_envolope(msg, from_addr, to_addrs, subject='This is a html mail.')

     email_obj.send_mail(from_addr, to_addrs + cc_addrs, msg)

     """

     # Send email with attachments.

     email_obj = BTEmail(host='smtp.sina.com', port=465, username=username, password=password)

     msg = email_obj.construct_msg(r'content\mail.html', 'html', 'utf-8', attach_flag=True, attachpath=r'attachment')

     email_obj.make_envolope(msg, from_addr, to_addrs, subject='A html mail with attachments.')

     email_obj.send_mail(from_addr, to_addrs + cc_addrs, msg)

 if __name__ == '__main__':

     main()