[Dovecot] Custom 'quota exceeded' message + Sieve script from database

[Przemyslaw Wegrzyn]

Hi!

I'm quite new to Dovecot. helping my friend to migrate from Courier-IMAP 
to something more efficient, we are evaluating Dovecot at the moment.

I had to prepare 2 small patches for Dovecot to suit our needs, and I've 
decided to post it here. I'm not fully familiar with Dovecot 
architecture yet, I'd appreciate if someone could look if these changes 
make sense (i.e. doesn't break anything). And of course, maybe someone 
is interested as well.

1. Customized "quota exceeded" message.

http://czajnick.sitenet.pl/dovecot/dovecot_1.0.9_quota_exceeded_message.diff

- quick hack to let me define custom message instead of typical "Quota 
exceeded", simply by using plugins { quota_exceeded_message = ... }. 
Browsing this mailing list I've seen some posts about such feature being 
implemented in Dovecot. Is it done in a similar way? Which stable 
version is the first to include this functionality?

2. Sieve filter modification

http://czajnick.sitenet.pl/dovecot/dovecot_sieve_1.0.2_envscript_patch.diff

In our systems we currently use a modified maildrop MDA that picks the 
filter script from the database instead of the file. This has proven 
useful - end-user's administration panel doesn't need any special 
permissions (or networking capabilities), as it doesn't need to access 
the filesystem - it is reduced to a plain database web-app.

The patch above makes the delivery agent check for the sieve script 
present in SIEVE_SCRIPT environment variable. If this is the case, env 
var content is used instead of the script stored in a usual file pointed 
to by SIEVE variable. This makes it trivial to pass the script from the 
database using base dovecot functionality.

A minor drawback of such solution is that the script is re-compiled on 
each delivery, but I don't think it takes much time to compile a few 
lines of a script using (f)lex/bison-or-yacc parser. Yes, I've noticed 
the sieve-manage patch, but I don't want the complexity of managing 
sieve script over the socket connection (if my understanding of the 
script is wrong, please correct me).

BR,
Przemyslaw