[Zope] Proposal for mail-in to Zope

[Simon Coles]

Hi,

We (NIP - in the form of Chris Withers, Stephen Harrison, and Simon 
Coles) have put some thought into the question of how to get emails 
into Zope, and have come up with a design which we thought we'd pass 
by the list before we start doing something.

The problem we are trying to solve is basically being to email 
"something@myserver.me.com" and that email ends up in the Zope ZODB 
processed in whatever way is appropriate.

We aren't worried about sending email, that's done well at the 
moment. We also wanted to keep things as simple and quick as possible 
:-) This means trying to avoid getting involved with mail systems as 
much as we can.

Most MTAs can be setup to pass an email to the stdin of a program. 
Sendmail will do this, and Exim (http://www.exim.org/) will also pay 
attention to what that program returns and queue the message for 
re-try later if it fails. So using Exim, we don't have to get into 
any messy stuff about queuing mails if the Zope server is down.

Some alternatives we considered and didn't go for:
	- write something in Zope to listen for SMTP connections, effectively
	  large portions of an MTA. This would be cool but painful.
	- pull mail from a POP or IMAP server. This had the downside that it
	  introduced polling into the system (slow) and also required something
	  to happen on a schedule, which doesn't happen in Zope yet.

So:
	- Within Exim, use the "pipe" transport to get email for a particular
	  host sent to a program on the standard input. If the program called
	  returns certain codes then Exim will queue the message and try again.

	- This program takes the email message and puts it into Zope, probably
	  by calling a DTML Method or something. This would probably be
	  configured by objects in the Zope ZODB which say effectively "When
	  you get email for this address, then call this Method".

	- The DTML Method is responsible for doing the right things to get
	  the email message into the ZODB in whatever form is appropriate.

We haven't yet figured out how to make sure the above mail handling 
program can find all the relevant configuration documents. Is there 
some way of efficiently finding all instances of a particular ZClass?

(Chris W. still isn't sure that's how the configuration will work but 
that's the plan for the moment, so any thoughts would be appreciated)

What we'll do is a first version that hard codes everything in the 
above script and prove the principle of the thing, and then move onto 
the configuration.


Does this sound like what people need? Any thoughts, comments, warnings?


I don't know yet what kind of schedule we'll be able to do this on 
but drop me a mail and when there's something to play with we'll let 
you know.




Simon
-- 
--------- My opinions are my own, NIP's opinions are theirs ----------
Simon J. Coles                                 Email: simon@nipltd.com
New Information Paradigms                  Work Phone: +44 1344 753703
http://www.nipltd.com/                     Work Fax:   +44 1344 753742
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