[Dovecot] 0.99.11 (CentOS4 or RHEL4) to 1.0.rc7 upgrade folder issue

[Rich West]

When we upgraded from uw-imapd to dovecot 0.99, and then over to the 1.0
series (which is FAR better than 0.99 which was light years ahead of
uw-imapd), we bumped in to a similar problem in our testing environment.

The end result was that the .mailboxlist, which was used by uw-imapd
needed to be migrated over to .subscriptions for dovecot
1.0rc-something.  Having both files in place really caused some
confusion since older versions of dovecot supported .mailboxlist (if I
remember correctly).  However, once the files were sorted out,
Thunderbird, Outlook, IMP (horde), all were able to see the same
subscribed folders without forcing any user to re-subscribe.

-Rich

> [Sending this again from the email account that I actually have
> subscribed to the list - hopefully won't be a dup...]
>
> We have been running dovecot-0.99.11-2.EL4.rpm on CentOS4 (since that's
> the latest that ships with RHEL/CentOS) for a while. Aalso in parallel,
> we have been running  various 1.0 betas and RCs on a different port for
> a different set of more test-tolerant users.
>
> This weekend, I upgraded to 1.0.rc7, and made all users use this. I
> found a small issue.
>
> All our users have a large set of folders in their Maildir. For the
> users who got upgraded from 0.99.11 to 1.0.rc7 (well, the one user who
> accessed their mail so far since the upgrade...) their folders weren't
> showing up in Thunderbird any more.
>
> Deleting all the dovecot-* files in the Maildir didn't help.
>
> In the end, the user re-subscribed to all the folders and then they
> showed up. (FYI, this is a right-click operation on the account in the
> Thunderbird tree view, subscribe menu option, then re-check all the
> folder names).
>
> Is there anything that can be implemented in 1.0.rc7 so that users don't
> have to manually re-subscribe to everything, so the upgrade process in
> this situation is a little more transparent?
>
> Is this simply a matter of the different Dovecot versions naming the
> folders with different UUIDs (or whatever the IMAP protocol uses), or
> something else?