mailbox.py

#!/usr/bin/env python3
# Foundations of Python Network Programming, Third Edition
# https://github.com/brandon-rhodes/fopnp/blob/m/py3/chapter14/mailbox.py

import getpass, poplib, sys

def main():
    if len(sys.argv) != 3:
        print('usage: %s hostname username' % sys.argv[0])
        exit(2)

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

    p = poplib.POP3_SSL(hostname)
    try:
        p.user(username)
        p.pass_(passwd)
    except poplib.error_proto as e:
        print("Login failed:", e)
    else:
        response, listings, octet_count = p.list()
        if not listings:
            print("No messages")
        for listing in listings:
            number, size = listing.decode('ascii').split()
            print("Message %s has %s bytes" % (number, size))
    finally:
        p.quit()

if __name__ == '__main__':
    main()