The mailing list for listmasters using Sympa

[address@concealed]

Dilyan Palauzov wrote:

> 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.

Looking at Sympa authorization scenario can show you that there is not a 
static definition of allowed message senders. A message can be rejected 
because of an attachment or some header or because some  complex 
condition (example : user is not from domain X and then can't send 
message with attachment unless he is subscriber of list Y etc etc). The 
only way to known if a message will be rejected or not is to run the 
appropriate scenario script. We could develop a new entry point for 
Sympa.pl in order to test a message without submitting it to the list 
(cat xx.msg | sympa.pl --test_authorization). I don't think this could 
be easy but we can do the same on the soap server interface. This way 
anyone could provide milter or any other MTA plug in to test a message 
against Sympa authorization scenario.

At the moment, you can use reject,quiet in scenario so not any 
notification is returned by Sympa but this may be bigger problem.

Serge