POP and IMAP

POP and IMAP - Post Office Protocol and Internet Message Access Protocol

用来从 SMTP Server 上下载邮件的协议.

    POP - The Post Office Protocol
        通过 poplib 链接服务器,
        例子,
            import sys
            import poplib, email
            host = ''
            userid = 'userid'
            PW = 'PW'
            storedir = '' # email stored directory(the mailbox)
            P = poplib.POP3(host)
            try:
                P.user(userid)
                P.pass_(PW)
            except poplib.error_proto as e:
                print("Login failed: ", e)
                sys.exit()

            maillist = P.list()[1]   # the list of message in the mailbox
            print(" %d mails." % len(maillist))
            dellist = []

            for item in maillist:   # email download
                number, octets = item.split(' ')
                print("Start downloading mail %s (%S Bytes)" % (number, octets))
                lines = P.retr(number)[1]  # retrieve the 'number'th email
                msg = email.message_from_string("
".join(lines)) #  email object
                with open(storedir) as FH:
                    FH.write(msg.as_string(unixfrom=1) + "
")
                dellist.append(number)
                print("Downloaded mail %s (%S Bytes)" % (number, octets))

            counter = 0
            for num in dellist:   # delete email
                counter += 1
                print("Deleting mail %d of %d" %(counter, len(dellist)))
                P.dele(number) # delete mail

            print("%d emails were deleted from server" % counter)
            P.quit() # logout from server

    IMAP - Internet Message Access Protocol
        相比于 POP 协议  IMAP 更加完善,且功能更加强大
        例子, opens a mailbox and retrieves and prints all messages:

            import getpass, imaplib
            M = imaplib.IMAP4()
            M.login(getpass.getuser(), getpass.getpass())
            M.select()
            typ, data = M.search(None, 'ALL')
            for num in data[0].split():
                typ, data = M.fetch(num, '(RFC822)')
                print('Message %s
%s
' % (num, data[0][1]))
            M.close()
            M.logout()

Reference,
    python doc,
        https://docs.python.org/3/library/imaplib.html