web2mail_server.py

#!/usr/bin/python

# File: web2mail_server.py
# Author: Michael Stevens <mstevens@etla.org>
# Copyright (C) 2010

#    This file is part of web2mail.
#
#    web2mail is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    web2mail is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with web2mail.  If not, see <http://www.gnu.org/licenses/>.


from twisted.mail import smtp, maildir
from zope.interface import implements
from twisted.internet import protocol, reactor, defer
import os
from email.Header import Header

SMTP_PORT = 1025

class MaildirMessageWriter(object):
    implements(smtp.IMessage)

    def __init__(self, userDir):
        if not os.path.exists(userDir): os.mkdir(userDir)
        inboxDir = os.path.join(userDir, "Inbox")
        self.mailbox = maildir.MaildirMailbox(inboxDir)
        self.lines = []

    def lineReceived(self, line):
        self.lines.append(line)

    def eomReceived(self):
        print "Message data complete."
        self.lines.append("")
        messageData = "\n".join(self.lines)
        return self.mailbox.appendMessage(messageData)

    def connectionLost(self):
        print "Connection lost unexpectedly!"
        del(self.lines)

class LocalDelivery(object):
    implements(smtp.IMessageDelivery)

    def __init__(self, baseDir, validDomains):
        if not os.path.isdir(baseDir):
            raise ValueError, "'%s' is not a directory" % baseDir
        self.baseDir = baseDir
        self.validDomains = validDomains

    def receivedHeader(self, helo, origin, recipients):
        myHostname, clientIP = helo
        headerValue = "by %s from %s with ESMTP: %s" % (
            myHostname, clientIP, smtp.rfc822date())
        return "Received: %s" % Header(headerValue)

    def validateTo(self, user):
        if not user.dest.domain in self.validDomains:
            raise smtp.SMTPBadRcpt(user)
        print "Accepting mail for %s..." % user.dest
        return lambda: MaildirMessageWriter(
            self._getAddressDir(str(user.dest)))

    def _getAddressDir(self, address):
        return os.path.join(self.baseDir, "%s" % address)

    def validateFrom(self, helo, originAddress):
        return originAddress

class SMTPFactory(protocol.ServerFactory):
    def __init__(self, baseDir, validDomains):
        self.baseDir = baseDir
        self.validDomains = validDomains

    def buildProtocol(self, addr):
        delivery = LocalDelivery(self.baseDir, self.validDomains)
        smtpProtocol = smtp.SMTP(delivery)
        smtpProtocol.factory = self
        return smtpProtocol

if __name__ == "__main__":
    import sys
    mailboxDir = sys.argv[1]
    domains = sys.argv[2].split(",")
    reactor.listenTCP(SMTP_PORT, SMTPFactory(mailboxDir, domains))
    reactor.run()