ohms4tehpuur/smtproutes

A simple, Sinatra inspired, SMTP routing server.

SMTPRoutes

SMTPRoutes is a light weight SMTP server built on top of Secure-SMTPD.

It's what you'd get if Sinatra and SMTP had a baby.

Installation

$ easy_install smtproutes

Note: You must use easy_install here. If you use pip there will be conflicting dependencies and things won't work.

Routes

Routes are specified via a regex provided in the route decorator.

from smtproutes import Route
from smtproutes.decorators import route

class ExampleRoute(Route):
	@route(r'myroute@.*')
    def my_route(self):
		print self.mailfrom.email

When invoked a route will have access to the following instance variables:

• self.message the parsed email message.
• self.mailfrom a contact object indicating who the message was received from.
• self.tos an array of contact objects extracted from the To field.
• self.ccs an array of contact objects extracted from the CC field.
• self.bccs an array of contact objects extracted from the BCC field.

Any named groups specified in the route regex will be availble as instance variables.

class ExampleRoute(Route):
    
	@route(r'(?P<prefix>open)@(?P<suffix>.*)')
    def open_route(self):
        print "%s at %s sent the message: \n\n %s" % (
            self.prefix,
            self.suffix,
            self.message
        )

Sender Authentication

Email is vulnerable to spoofing attacks. SMTPRoutes allows you to provide an authentication object to protect against these.

An authentication class can be provided in the sender_auth kwarg of a route decorator.

@route(r'(?P<prefix>spf)@(?P<suffix>.*)', sender_auth=SPFAuth)
def spf_route(self):
    print "%s at %s sent the message: \n\n %s" % (
        self.prefix,
        self.suffix,
        self.message
    )

Currently the following sender authentication methods are supported:

• DKIMAuth authenticates using a DKIM signature. (http://en.wikipedia.org/wiki/DomainKeys_Identified_Mail)
• SPFAuth authenticates using an SPF record. (http://en.wikipedia.org/wiki/Sender_Policy_Framework)
• GmailSPFAuth authenticates against Google's SPF records, regardless of sender (useful for Google Apps).

You can provide multiple authentication approaches in the sender_auth kwarg, if any pass the route will be called:

@route(r'(?P<prefix>spf_google)@(?P<suffix>.*)', sender_auth=[SPFAuth, GmailSPFAuth])
def google_apps_spf_route(self):
    print "%s at %s sent the message: \n\n %s" % (
        self.prefix,
        self.suffix,
        self.message
    )

Running a Server

The server is a thin abstraction on top of secure-smtpd (https://github.com/bcoe/secure-smtpd).

• SSL is supported.
• Basic SMTP authentication is supported.

Create an instance of the server using any of the configuration options specified in the secure-smtpd project.

from smtproutes import Server

server = Server(('0.0.0.0', 25), None)

Once the server is created, you can register routes with it and start it running:

from example_route import ExampleRoute
server.add_route(ExampleRoute).start()

The server will now be listening on port 25 for inbound SMTP messages.

The Contact Objects

self.mailfrom, self.tos, self.ccs, and self.bccs each contain instances of contact objects:

• contact.name the name extracted from the email address.
• contact.email the email of the contact.

The Message Object

self.message is available as an instance variable when a route is executed.

self.messsage is a subclass of email.message.Message described here: http://docs.python.org/library/email.message.html#module-email.message

Extended functionality:

• message.body the plain text body of the message.
• message.attachments the attachments on the message.

Additional Support for Attachments

self.message has been extended upon to include an attachments property, which contains a list of pre-processed attachments:

• attachment.filename the filename of the attachment.
• attachment.data the binary data of the attachment.
• attachment.extension the file extension of the attachment.
• attachment.mime_type the mime type of the attachment.