[Dovecot] Plugin mail-filter tangles

[Axel Luttgens]

Le 28 mai 2014 à 16:41, Stanislas SABATIER a écrit :

> [...]
> I tried to explain my specific case in my first post to the list (first
> mail of this thread, may 24) :
> [...]
> To sum up, here are the headers : (CASE 1)
> 
>    *from : user1 at mydomain1*
>    to: someone at yahoo.com
>    CC: user2 at mydomain2, user3 at mydomaine3
> 
> 
> In this specific situation, Dovecot receives one email from Postfix for
> user2 and user3. Dovecot is creating two user contexts, load mail-filter
> plugin with user2 params, it saves the email, then it loads mail-filter
> plugin with user3 params BUT, instead of reading the original email from
> Postfix, Dovecot is trying to read the email from user2 (I see an
> istream opening in logs) and pass it to user3. That fails because, in
> this context, Dovecot can't access user2's email that has been encrypt
> by my mail-filter.

Hello Stanislas,

Indeed, the above describes your intial post.
A case I described as being a bit frightening, since it could raise some privacy concerns.

> [...]
> To sum up, here are the headers : (CASE 2)
> 
>    *from : someone at gmail.com*
>    to : someone at yahoo.com
>    CC: user2 at mydomain2, user3 at mydomaine3
> 
> 
> In this situation, Dovecot receives one email from Postfix for user2 and
> user3 (same situation than case 1). Dovecot is creating two user
> contexts, load mail-filter plugin with user2 params, it saves the email,
> then it loads mail-filter plugin with user3 params and save the email
> with user3 params. And I can say « working perfectly » !
> 
> [...]

And here, you confirm the new info throughout this thread.

So, the nature of the envelope sender would have an impact on how an email is delivered by Dovecot's LMTP to local recipients.

Up to now, the only path I could find for bringing some confusion among recipients would be in the handling provided by client_input_data_write_local() of src/lmtp/commands.c.
Even if the link with the envelope sender still remains obscure to me...
Anyway, managing to have Postfix sending one message per recipient might prove useful for diagnosing the problem.

HTH,
Axel