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Re: Proof of concept: Mailing list "software" without MTA




	Hi.

On Thu, Oct 25, 2018 at 03:57:32PM -0400, rhkramer@xxxxxxxxx wrote:
> Sometimes things just stick in my head until I do something to get them out -- sorry. ;-)

That's OK. Listening all those voices in the head - that's really
disturbing ;)


> I am 100% sure I can create mailing list software that does not need an MTA.  If this post gets to the list, that is proof -- read on if you wish.  (Of course, someone might argue that I've created an MTA, and, maybe, in some sense, I have, but I have avoided the need to set up a "real" MTA which has always proved a very frustrating task for me.)

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It says here what you've used Google's MTA.
It even has correct DKIM signature, and that's something that means you
haven't forged the headers.


> Also, as this is a proof of concept rather than a polished finished thing, I've done a lot of steps by hand and have not included all the safety checks (e.g., avoiding mail loops, which I'd have to learn how to do) that I would expect in a polished product.

So, to rephrase - you can create a maillist that does not need your MTA.
As long as you accept the risks - like, for instance, instant
termination of your maillist at Google's leasure - it will probably
work.


> Basically, instead of setting up an MTA, I've used my "windows style" email client (kamil -- an MUA, aiui) to do what is, to me, the heavy lifting.
> 
> A "real" mail list program (or "suite" of programs) using this approach would work something like this:
> 
>    * a filter in kmail would watch for emails / posts directed to the mailing list, and would put those in a special folder (probably named with the name of the mailing list and maybe some prefix or postfix (not the program ;-)
>    
>    * a program (possibly a bash script) would watch that folder (check it periodically), and when a file is found:

They invented inotify(7) for that 10 years ago. Install incron.

>       * move it to a work location (removing it from the original folder)
>       * process it in various ways using tools like awk, sed, or similar to do things like:
>          * optionally check the list of subscribers to make sure it came from a subscriber (unless I want to treat it as an open mail list) -- if from a non-subscriber (or a banned user / spammer), optionally send a rejection message (I found in my "administration" of some yahoo groups, that it often worked better not to send a rejection message to a known spammer -- if you send a message, they often try to subscribe (or resubscribe) and then resend the spam -- if you don't send a message, they often seem to assume that there is no problem, never realizing that their messages weren't getting to the list)

SpamAssassin, anyone?

>          * optionally call it to the attention of the owner of the list (or of the computer it is running on) if the list (or this user) is to be moderated
>          * change some of the message headers as appropriate (including generating a new unique messageID (maybe using `date +%s.%N' and some text string reflecting the name of the mailing list

formail from procmail or reformail from maildrop.
And changing existing Message-ID header is a really bad idea.

>          * perhaps add things like a new header and footer to the text of the message (like the name of the maillist or group, a MOTD, how to unsubscribe, ...)

Good luck reassembling all those base64/uuencoded e-mails.
Even single Unicode smiley like this ☺ will lead to funny results.

Reco