dovecot - Aug 2012 - Is it possible to save only some messages compressed to mdbox? (2.1.6)

I'm trying to save some messages as compressed (via zlib plugin) and it
doesn't seem to work.

Here's a log line (I'm logging to stderr):

d k 1345467448.705591500 1345467448.705596500 1345467448.974808500 1650
<XXXXXXXXXXXXXXXXXXXXXXXXXX at YYY.ruhr-uni-bochum.de>
local.jost.krieger+hirn at ruhr-uni-bochum.de 10909 80
Extra: -o plugin/zlib_save_level=9 -o plugin/zlib_save=bz2
lda(kriegjcb): Info: msgid=<20120820125728.58CC9172B6C at
c2-4-7.noc.ruhr-uni-bochum.de>: saved mail to Hirn-2012-08
did 0+0+1

This probably doesn't make much sense to anyone except the last line but 1.
It is a somewhat complicated qmail/maildrop/dovecot setup, which works
for the standard cases.
The Extra gets interpolated into the lda command and this works because
an incorrect option blows up the delivery.

The mails arrive uncompressed.

So here's the questions:

1. Is it possible to have compressed/uncompressed mails mixed in an
   mdbox?
2. Will it work via "-o" in lda delivery?

I tried to find out in the source but found it hard to see which options
are pulled in when.

Thanks
Jost Krieger
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On 20.8.2012, at 16.06, Jost Krieger wrote:
> So here's the questions:
> 
> 1. Is it possible to have compressed/uncompressed mails mixed in an
>   mdbox?
Yes. Compression is detected on a per-mail basis.
> 2. Will it work via "-o" in lda delivery?
> 
> I tried to find out in the source but found it hard to see which options
> are pulled in when.
-o can override all settings that are handled by the running process itself, so
yes that includes compression stuff.