Downloading emails via IMAP repacks the mailbox and resets the seen flag

[Timotheus Pokorra]

Hello Bron,

> Version 10 is a 2.3.x mailbox format.  You should upgrade to 2.5 format as documented in the upgrade notes.>
>
> Kolab should probably have run the update as part of their package upgrade... hmm.

There is no package upgrade mechanism for Kolab, so I had to do it
following the manual upgrading steps.
That worked for all mailboxes but one.

Your information about the old mailbox format convinced me that this
particular mailbox was broken (probably already the upgrade did not
work because it was broken in some way).
So I deleted the cyrus.* files, and did a reconstruct, and now the
mailbox works fine.
I lost the unread status of the messages but at least it works.

Thank you,
  Timotheus