Developers of Sympa

[Patrick von der Hagen <address@concealed>]

Hi all,

as I mentioned some time ago, I try to reduce the number of bounces
caused by my system, because misdirected bounces have become an
increasing problem, not only because Spamcop.net really really doesn't
like them.

I'm still running listserv, which is a terrible source of such
misdirected bounces. Using Sympa (I expect so move from "testing" to
"production" soon) would already reduce the number of misdirected
bounces, due to the fine-grained scenarii.

However, I'd like to have an even better solution and reject e-mails
during the smtp-transaction, whenever possible.

After finally having a look at the documentation of Sendmail::Milter and
the sourcecode of sympa, this seems to be quite easy.

I just need to register one callback with Sendmail::Milter which is to
be invoiced after the message has been received. That callback would
save the message to disk and perform quite literally what DoFile and
DoMessage perform right now, but instead of actually processing the
message it should just return what action is to be processed.

All it would take is a quiet day, copy'n'paste, some look and lots of
coffee. ;-)

Problems:
- it would not be very efficient, the message would have to be
transfered to sympa twice and lots of the processind would happen twice,
too.
- I would start by doing lots of copy'n'paste, which would be a
maintenance nightmare, but currently I would prefer not to modify the
sympa sourcecode. However, a later refactoring of DoFile and DoMessage
would be a good idea, if a sympa-milter would actually a) work and b)
find some users.
- Using sympa-milter, a message having multiple list-recipients could
only be reject for all recipients during the smtp-transaction, not for
individual recipients. What should happen if a message is sent to
multiple lists on a server, some of which would accept that message
while some would reject? Solution a: accept the message if one of the
recipients accepts it. Solution b: configure the MTA querying
sympa-milter to only accept one recipient at a time.

There might be more issues, so I'd be happy to get some feedback
regarding this idea before actually implementing it.

-- 
CU,
   Patrick.

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