Python IMAP/POP3收取并解析邮件

MIME邮件格式

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------=_Part_183728_654166346.1544772945612
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------=_Part_183730_484598546.1544772945613
Content-Type: text/plain; charset=GBK
Content-Transfer-Encoding: base64
 
c2tkaGFza2pkaDG72ODB1/fPsrPJuaYx
------=_Part_183730_484598546.1544772945613
Content-Type: text/html; charset=GBK
Content-Transfer-Encoding: base64
 
PGRpdiBzdHlsZT0ibGluZS1oZWlnaHQ6MS43O2NvbG9yOiMwMDAwMDA7Zm9udC1zaXplOjE0cHg7
Zm9udC1mYW1pbHk6QXJpYWwiPnNrZGhhc2tqZGgxu9jgwdf3z7KzybmmMTwvZGl2Pjxicj48YnI+
PHNwYW4gdGl0bGU9Im5ldGVhc2Vmb290ZXIiPjxwPiZuYnNwOzwvcD48L3NwYW4+
------=_Part_183730_484598546.1544772945613--
 
------=_Part_183728_654166346.1544772945612
Content-Type: text/plain; name="=?GBK?Q?=B2=E2=CA=D422.txt?="
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="=?GBK?Q?=B2=E2=CA=D422.txt?="
 
vM6088/Dv9W85Lu5yse087/Nu6e94r72DQo=
------=_Part_183728_654166346.1544772945612--

这是一封邮件的原始数据，每一封邮件都有From,To,Date等字段，传输编码有两种，Base64和Quoted-printable。目前MIME邮件中的数据编码普遍采用Base64编码或Quoted-printable编码来实现。

Base64编码：
  Base64编码的目的是将输入的数据全部转换成由64 个指定ASCII字符组成的字符序列， 这64个字符由{‘A’-‘Z’， ‘a’-‘z’， ‘0’-‘9’， ‘+’， ‘/’}构成。编码时将需要转换的数据每次取出6bit，然后将其转换成十进制数字，这个数字的范围最小为0，最大为63，然后查询{‘A’-‘Z’， ‘a’-‘z’， ‘0’-‘9’， ‘+’， ‘/’}构成的字典表，输出对应位置的ASCII码字符，这样每3个字节的数据内容会被转换成4个字典中的ASCII码字符，当转换到数据末尾不足3个字节时，则用“=”来填充。

Quoted-printable编码：

  Quoted-printable编码的目的也是将输入的信息转换成可打印的ASCII码字符，但它是根据信息的内容来决定是否进行编码，如果读入的字节处于33-60、62-126范围内的，这些都是可直接打印的ASCII字符，则直接输出，如果不是，则将该字节分为两个4bit，每个用一个16进制数字来表示，然后在前面加“=”，这样每个需要编码的字节会被转换成三个字符来表示。

boundary="----=_Part_183728_654166346.1544772945612" 这是定义一个标识分割符，结束的时候加入 --，而在这个范围内可以申明其他的标识。结束标识与定义的时候是相对应的，而中间你有多个部分(段)都没什么关系。抬出邮件格式图对应起来看就知道了：

POP3代码

 def receive_email_pop3(self):
        
        try:
            email_server = poplib.POP3_SSL(host=self.server_host, port=self.server_port, timeout=10)
            print("connect server success............")
        except:
            print("connect timeout...................")
            return
        try:
            email_server.user(self.email_address)
        except:
            print("sorry the given email address seem does not exist")
            return
        try:
            email_server.pass_(self.auth_code)
            print("password correct,now will list email")
        except:
            print("sorry the given username does not seem correct")
            return

        emailMsgNum,emailSize=email_server.stat()
        print('email number is %d and size is %d'%(emailMsgNum, emailSize))  
        # print('list is {}'.format(email_server.list()))
        email_count = len(email_server.list()[1])
        
        time.sleep(2)

        # 遍历所有邮件
        for i in range(1,email_count+1):

            try:
                contents= email_server.retr(i)[1]
                email_content = b'\r\n'.join(contents)
                # email_content = email_content.decode('utf-8')
                try:
                    # msg=email.message_from_bytes(email_content)
                    # date=msg.get('date')
                    # mail_info.ReceiveDate=self.get_time_stamp(date)
                    self.parse_emial(email_content)

                except:
                    print(email_content)
                    print('decode email failed.....................')
                # email_content = email_content.decode('utf-8','ignore')
                # msg = Parser().parsestr(email_content)
                
            except Exception as e:
                print(e)
                print('pop3 unknow error..............................')
                continue
            
        # 关闭连接
        email_server.close()

IMAP代码

也可以用imapclient进行获取

    def receive_email_imap(self):

        server = imaplib.IMAP4_SSL(port = self.server_port,host = self.server_host)
        if server is not None:
            
            res=server.login(self.email_address,self.auth_code)
            print(res)
            if res!='':
                 mail_boxes=[]
            boxes=server.list()[1]
            for l in boxes:
                mail_boxes.append(l.decode('utf-8').rsplit('"/"')[1])
            # mail_boxes=mail_boxes[1:]
            

            for box in mail_boxes:
                if box.lstrip()=='"&UXZO1mWHTvZZOQ-"':
                    continue
                server.select('{}'.format(box.lstrip()),readonly=True)
                data=server.search(None,'ALL')[1]
                # print('data is {}'.format(data))
                email_count = len(data[0].split())
                total+=email_count

            for box in mail_boxes:
                # print(box)
                try:
                    server.select('{}'.format(box.lstrip()),readonly=True)

                    unseen=server.search(None,'UNSEEN')[1]
                    unseen_list=unseen[0].split()

                    # Recent Seen Answered Flagged Deleted Draft
                    data=server.search(None,'ALL')[1]
                    email_count = len(data[0].split())
                    print('email count is {}'.format(email_count))

                    # email_count
                    for i in range(0,email_count):
                        try:

                            latest_email_uid = data[0].split()[i]
                            try:
                                
                                email_data = server.fetch(latest_email_uid, '(RFC822)')[1]
                                raw_email = email_data[0][1]

                            except Exception as ex:
                                print('imap fetch unknow error.............')
                            try:
                                self.parse_emial(raw_email)
                            except Exception as ec:
                                # print(raw_email)
                                print(ec)
                                print('decode email failed.....................')
                            
                        except Exception as e:
                            print(e)
                            print('imap unknow error..............................')
                            continue

                except:
                    pass
                server.logout()

邮件解析

本次解析采用了一个eml_parser的模块儿进行解析，也可采用emial模块进行解析，但是效果不是特别好，有很多东西没法解析。

def parse_emial(self,msg):
        eml=eml_parser.eml_parser.decode_email_b(msg,include_raw_body=True,include_attachment_data=True)
        # raw_size=len(msg)/1024
        raw_size=len(msg)
        header = eml.get('header')
        body = eml.get('body')    # type: list
        attachments = eml.get('attachment')
        
        # 密送是bcc，不一定能获取
        # header['to'] 应该也可以读取到数据
        to=[]
        try:
            to=header['header']['to']
        except:
            try:
                to=header['to']
            except:
                to=[]

        # from
        from_=header.get('from')

        subject=header.get('subject')
        
        # 获取抄送
        cc = header.get('cc')

        # 保存路径
        res_dir=self.frame.get_task_res_path()
        atta=self.parse_attachment(attachments,res_dir)
 
        # localtimestamp=0
        # try:
        #     localtimestamp=int(time.mktime(header['date'].timetuple()))
        # except:
        #     print('date format error......{}'.format(header['date']))
        # else:
        #     mail_info.ReceiveDate=localtimestamp


    # def get_eml_content(self,mail_content):
    #     """分析content字段"""
    #     if mail_content is None:
    #         return
    #     if mail_content is not None:
    #         if len(mail_content) > 14 and 'html' in str(mail_content[:14]).lower():
    #             mail_info.Html=mail_content
    #         else:
    #             mail_info.Text=mail_content.replace('\r\n', ' ')


    def parse_attachment(self,attachments, save_path):
        size=0
        file_list=[]

        if attachments is None:
            return [], size
        for file in attachments:

            file_name = file.get('filename')
            file_size = file.get('size')
            
            size+=file_size

            # content_header = file.get('content_header')  # type: dict

            # save_path=os.path.join(save_path,file_name)
            file_name = self.save_attachment_file(file.get('raw'), save_path, file.get('filename'))
                
            # 保存所有文件列表
            file_list.append(file_name)


        return file_list, size


    def save_attachment_file(self, raw, save_path,file_name):
        
        try:
            raw = base64.b64decode(raw)
            file_path=os.path.join(save_path,file_name)
            with open(file_path, 'wb') as fp:
                fp.write(raw)

        except Exception as e:
            print('解码出错,{}'.format(e))
        
        return file_path

邮箱文件夹

这里的 “&UXZO1mWHTvZZOQ-”是IMAP-UTF7编码，可以用imapclient模块儿进行解码。

注意事项

-授权码需要自己配置，一般第三方登录都是采用授权码，尤其是163，为了推广邮箱大师，授权码登录也会被拦截，还需要另外设置，网上有个链接地址：http://config.mail.163.com/settings/imap/[e-mail]，设置之后是不会在收到拦截邮件的，但奇怪的是Foxmail是不会被拦截的(暂时不太明白为什么会这样，有知道的小伙伴可以留言告知下)