The mailing list for listmasters using Sympa

[Dilyan Palauzov <address@concealed>]

Dear Hargitai,

Everybody who manages mailing list(ML) server has the same problems. I  
was thinking how to reduce the bounces. I took into account, that a  
software for mailing list can hardly provide real-time checks if a  
mail is going to be distributed or not, and came to a bright idea:

  Create a Sieve (RFC 3028) script, that makes a sieve refuse  
(http://www.ietf.org/internet-drafts/draft-ietf-sieve-refuse-reject-03.txt)  
whenever a mail is 100% sure, that it will not be distributed over a  
list. This Sieve script shall refuse the mails, when their  
envelope_sender/from:/sender: ensure that the mail will be bounced by  
the ML-software, or when the mail is too big for a mailing list, or  
when it contains certain headers, ensuing the mail will be rejected.  
The SMTP-error messages the sieve script gives shall be the same, that  
the bounces contains. This sieve script shall be updated by the  
ML-software, whenever the conditions change (subscribers are added,  
list configuration is addopted, etc). The sieve-script shall use only  
capabilities, listed in a sympa.conf configuration. Thus if  
"variables" is permitted in sieve.conf, then the exported sieve  
scripts can contain it.

  Next, implement Sieve in a MTA. I personally would like to create a  
sendmail filter (sieve-milter) that does the job, based on the sieve  
implementation in cyrus-imap. To my knowledge, at the moment only exim  
as MTA offers partly support for Sieve  
(http://exim.netmirror.org/exim-html-4.30/doc/html/filter_2.html)  
however without the ability to not-accept mails.

  Anotgher option, is to export regularly for every manages list a  
list of e-mails, which are allowed to send mails to the list, and  
create a specific plugin per MTA, that checks if that person is  
allowed to write, and smtp-reject otherwise. However this idea is not  
that general as the previous one, where one can reject smap mails, or  
big mails, or mails containing only html-part, where a list allows  
only plain text (I am not 100% sure, if a sieve allows to filter  
mails, having only html-part, but for sure we can extend the sieve  
language, if needed).

  Greetings,
      Дилян



----- Message from address@concealed ---------
    Date: Mon, 16 Oct 2006 15:45:28 +0200
    From: Hargitai Gabor <address@concealed>
Reply-To: Hargitai Gabor <address@concealed>
 Subject: [sympa-users] Problems with spamcop.net
      To: address@concealed


> Hi all,
>
> in the recent months we had problems with spamcop.net. They always put our
> Sympa server to blacklist because it sent mails to their spamtraps. I'm
> pretty sure that Sympa simply bounced back emails to fake addresses and
> unfortunately some of the fake addresses were spamtraps. Now we could contact
> them and they sent us such a mail and it was a message about rejection
> because the sender wasn't subscriber of the list. So my questions are:
>   - did anybody on the list have similar problem with spamcop or other
> anti-spam service? What are your experiences?
>   - as far as I know we can't turn off messages about automatic rejection if
> we can't solve this problem with spamcop. All we can do is that we don't send
> notification to the sender if his message goes to moderation.
>
> Thanks for your help in advance.
>
> --
> Cheers
> Gábor


----- End message from address@concealed -----