[Dovecot] Converting old emails to compressed format

[Wolfgang Rosenauer]

Hi,


On Fri, Feb 28, 2014 at 12:18 AM, Renaud Allard <renaud at allard.it> wrote:
>
> I know this question has already been asked, but I would really like a
> solution here as I tried all I could find on the wiki or mail archives
> I am now running dovecot 2.2.12
> Compression works fine for new mails, so zlib works
> Mails are currently stored using dbox
>
> So I tried for testing
> dsync -D -v mirror -u user -m Archives dbox:~/temp
> dsync -o "plugin/zlib_save=xz" -D -v mirror -u user -m Archives dbox:~/temp
> dsync -o "plugin/zlib_save=" -D -v mirror -u user -m Archives dbox:~/temp
> dsync -o "plugin/zlib_save=" -D -v mirror -u user -m Archives maildir:~/temp
> dsync -o "plugin/zlib_save=xz" -D -v mirror -u user -m Archives
> maildir:~/temp
>
> And also converting again those maildir messages to dbox (just in case it
> wouldn't work from dbox format)
> And also with backup instead of mirror
>
> None of this actually works, mails are indeed copied, but not compressed
>
> So I am wondering if there is a way to compress those mails?

I'm now facing the same issue with 2.2.13.
zlib is working for new mails but as opposed to some information I
found dsync (backup) does not convert old mails to compressed.
For example this post suggests that it should happen:
http://thr3ads.net/dovecot/2013/07/2663810-dsync-backup-mails-compressed
and also some Dovecot book also states to convert the mailbox just use
dsync backup after zlib is enabled.
Still I'm not able to make it work.

Any hints?


Thanks,
 Wolfgang