def PareMessageAttachMent(mail,PATH,mailID):
   #print "Start extracting attachments, the attachment name is: %s "%PATH
   contenttype = None
   for part in mail.walk():
      if not part.is_multipart():
          contenttype = part.get_content_type() 
          filename = part.get_filename()
          charset = part.get_charset()
          if filename==None:
             continue
          h=email.Header.Header(filename)
          dh=email.Header.decode_header(h)
          filename=dh[0][0]
          encodeStr=dh[0][1]
          if encodeStr != None:
             if charset == None:
                filename = filename.decode(encodeStr,'ascii')
             else:
                filename = filename.decode(encodeStr,charset)
          filename=os.path.split(filename)[1]                          #防止文件名出现全路径错误
          strinfo = re.compile('[\/\\\<>|?*:;"\r\n] ')
          filename1 = strinfo.sub('_',filename)
          filename2 = os.path.normcase(filename1)
      
          print "filename2 is: %s "%filename2
      
          if filename:                                                 ###解析邮件的附件内容
             fn=PATH+'/'+filename2
             if os.path.exists(fn)==False:
                try:
                   f=open(fn,'wb')
                except:
                   filenametmp = str(mailID)+'-'+random_str(12)+'.dat' #创建邮件附件失败时,尝试使用邮件ID+随机字符串
                   filenametmp1 = strinfo.sub('_',filenametmp)
                   fn = PATH+'/'+filenametmp1
                   print "filename1 is: %s "%fn
                   f=open(fn,'wb')
                try:
                   f.write(base64.decodestring(part.get_payload()))
                except:
                   pass
                f.close()
             else:
                continue

1#为附件提取代码
当附件名只有一行时:
print "filename2 is: %s "%filename2 正常

当 附件名换行时，如
filename="zhe shi yi feng ce shi you jian 20150427 1234567890123 &
123456.pdf"; 

print "filename2 is: %s "%filename2 显示的内容为 
123456.pdfiszhe shi yi feng ce shi you jian 20150427 1234567890123 &

你的函数里对filename做了多步处理. 在下面标出的#1, #2,...等位置中, 从哪一步开始结果变得不对?

def PareMessageAttachMent(mail,PATH,mailID):

   ...

          filename = part.get_filename() # 1

          ...

          filename=dh[0][0] # 2

          encodeStr=dh[0][1]

          if encodeStr != None:

             if charset == None:

                filename = filename.decode(encodeStr,'ascii')

             else:

                filename = filename.decode(encodeStr,charset)

          print filename                              # 3

          filename=os.path.split(filename)[1]                          #防止文件名出现全路径错误  # 4

          strinfo = re.compile('[\/\\\<>|?*:;"\r\n] ')

          filename1 = strinfo.sub('_',filename)                         # 5

          filename2 = os.path.normcase(filename1)               # 6

      

          print "filename2 is: %s "%filename2   

...