import poplib

# 输入邮件地址, 口令和POP3服务器地址:
email = raw_input('Email: ')
password = raw_input('Password: ')
pop3_server = raw_input('POP3 server: ')

# 连接到POP3服务器:
server = poplib.POP3(pop3_server)
# 可以打开或关闭调试信息:
# server.set_debuglevel(1)
# 可选:打印POP3服务器的欢迎文字:
print(server.getwelcome())
# 身份认证:
server.user(email)
server.pass_(password)
# stat()返回邮件数量和占用空间:
print('Messages: %s. Size: %s' % server.stat())
# list()返回所有邮件的编号:
resp, mails, octets = server.list()
# 可以查看返回的列表类似['1 82923', '2 2184', ...]
print(mails)
# 获取最新一封邮件, 注意索引号从1开始:
index = len(mails)
resp, lines, octets = server.retr(index)
# lines存储了邮件的原始文本的每一行,
# 可以获得整个邮件的原始文本:
msg_content = '\r\n'.join(lines)
# 稍后解析出邮件:
msg = Parser().parsestr(msg_content)
# 可以根据邮件索引号直接从服务器删除邮件:
# server.dele(index)
# 关闭连接:
server.quit()

import email
from email.parser import Parser
from email.header import decode_header
from email.utils import parseaddr

msg = Parser().parsestr(msg_content)

# indent用于缩进显示:
def print_info(msg, indent=0):
  if indent == 0:
    # 邮件的From, To, Subject存在于根对象上:
    for header in ['From', 'To', 'Subject']:
      value = msg.get(header, '')
      if value:
        if header=='Subject':
          # 需要解码Subject字符串:
          value = decode_str(value)
        else:
          # 需要解码Email地址:
          hdr, addr = parseaddr(value)
          name = decode_str(hdr)
          value = u'%s <%s>' % (name, addr)
      print('%s%s: %s' % (' ' * indent, header, value))
  if (msg.is_multipart()):
    # 如果邮件对象是一个MIMEMultipart,
    # get_payload()返回list，包含所有的子对象:
    parts = msg.get_payload()
    for n, part in enumerate(parts):
      print('%spart %s' % (' ' * indent, n))
      print('%s--------------------' % (' ' * indent))
      # 递归打印每一个子对象:
      print_info(part, indent + 1)
  else:
    # 邮件对象不是一个MIMEMultipart,
    # 就根据content_type判断:
    content_type = msg.get_content_type()
    if content_type=='text/plain' or content_type=='text/html':
      # 纯文本或HTML内容:
      content = msg.get_payload(decode=True)
      # 要检测文本编码:
      charset = guess_charset(msg)
      if charset:
        content = content.decode(charset)
      print('%sText: %s' % (' ' * indent, content + '...'))
    else:
      # 不是文本,作为附件处理:
      print('%sAttachment: %s' % (' ' * indent, content_type))

def decode_str(s):
  value, charset = decode_header(s)[0]
  if charset:
    value = value.decode(charset)
  return value

def guess_charset(msg):
  # 先从msg对象获取编码:
  charset = msg.get_charset()
  if charset is None:
    # 如果获取不到，再从Content-Type字段获取:
    content_type = msg.get('Content-Type', '').lower()
    pos = content_type.find('charset=')
    if pos >= 0:
      charset = content_type[pos + 8:].strip()
  return charset

+OK Welcome to coremail Mail Pop3 Server (163coms[...])
Messages: 126. Size: 27228317

From: Test <xxxxxx@qq.com>
To: Python爱好者 <xxxxxx@163.com>
Subject: 用POP3收取邮件
part 0
--------------------
 part 0
 --------------------
  Text: Python可以使用POP3收取邮件……...
 part 1
 --------------------
  Text: Python可以<a href="...">使用POP3</a>收取邮件……...
part 1
--------------------
 Attachment: application/octet-stream