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Downloading and Deleting Messages

You should now be getting the hang of POP: when using poplib you get to issue small atomic commands that always return a tuple inside which are various strings and lists of strings showing you the result. We are now ready to actually manipulate messages! The three relevant methods, which all identify messages using the same integer identifiers that are returned by list(), are these:

  • retr(num): This method downloads a single message and returns a tuple containing a result code and the message itself, delivered as a list of lines. This will cause most POP servers to set the “seen” flag for the message to “true,” barring you from ever seeing it from POP again (unless you have another way into your mailbox that lets you set messages back to “Unread”).
  • top(num, body_lines):This method returns its result in the same format as retr() without marking the message as “seen.” But instead of returning the whole message, it just returns the headers plus however many lines of the body you ask for in body_lines. This is useful for previewing messages if you want to let the user decide which ones to download.
  • dele(num): This method marks the message for deletion from the POP server, to take place when you quit this POP session. Typically you would do this only if the user directly requests irrevocable destruction of the message, or if you have stored the message to disk and used something like fsync() to assure the data’s safety.

To put everything together, take a look at, which is a fairly functional e-mail client that speaks POP. It checks your in-box to determine how many messages there are and to learn what their numbers are; then it uses top() to offer a preview of each one; and, at the user’s option, it can retrieve the whole message, and can also delete it from the mailbox.

import email, getpass, poplib, sys

if len(sys.argv) != 3:
    print 'usage: %s hostname user' % sys.argv[0]

hostname, user = sys.argv[1:]
passwd = getpass.getpass()

p = poplib.POP3_SSL(hostname)
except poplib.error_proto, e:
    print "Login failed:", e
    response, listings, octets = p.list()
    for listing in listings:
        number, size = listing.split()
        print 'Message', number, '(size is', size, 'bytes):'
        response, lines, octets =, 0)
        message = email.message_from_string('\n'.join(lines))
        for header in 'From', 'To', 'Subject', 'Date':
            if header in message:
                print header + ':', message[header]
        print 'Read this message [ny]?'
        answer = raw_input()
        if answer.lower().startswith('y'):
            response, lines, octets = p.retr(number)
            message = email.message_from_string('\n'.join(lines))
            print '-' * 72
            for part in message.walk():
                if part.get_content_type() == 'text/plain':
                    print part.get_payload()
                    print '-' * 72
        print 'Delete this message [ny]?'
        answer = raw_input()
        if answer.lower().startswith('y'):
            print 'Deleted.'

If you run this program, you’ll see output similar to this:

[email protected]:~/Python_files# python my_gmail_acct
Message 1 (size is 1847 bytes):
From: [email protected]
To: Brandon Rhodes <[email protected]>
Subject: Backup complete
Date: Tue, 13 Apr 2010 16:56:43 -0700 (PDT)
Read this message [ny]?
Delete this message [ny]?