Hello,
> We tried using offlineimap / imapsync, but theses solutions doesn't
> seems very good either, poor performances,
Ok for the bad performances of imapsync.
Did you really try offlineimap and found it slow?
> and the big problem is that if a mail is moved or deleted after the
> last sync, it won't be the case when running a new sync. (at least
> with imapsync).
No problem at all if you read the imapsync help or the README file.
There are two options to have an actual "live" copy.
> So for us, the best solution appear to make a tgz of
> each mailboxes (We have 200 acounts), and we could restore
> it if our Zimbra server fail.
Backups are good all the time.
> To conclude, I'm just looking for a way to convert a backup
> tgz to maildir format
A backup tgz keeps a maildir format as is, no conversion to do.
It seems I didn't understand your issue or your never backup
and restored any directory with tar.