[Dovecot] Migration between namespaces breaks outlook on mac's

[Timo Sirainen]

On Thu, 2012-05-17 at 15:59 +0300, Mark Zealey wrote:
> We're now migrating customers onto a dovecot-2 platform, switching from 
> Maildir to sdbox (using dsync mirror) & changing the namespace at the 
> same time. New namespace configuration looks like (as taken from 
> http://wiki2.dovecot.org/Namespaces)
> 
> # This is for courier-imap namespace compatability
> namespace {
>      type = private
>      separator = /
>      prefix =
>      inbox = yes
> }
> 
> namespace {
>      type = private
>      prefix = INBOX.
>      separator = .
>      inbox = no
>      hidden = yes
>      list = no
>      alias_for =
> }
> 
> For 99% of clients this works fine eg thunderbird on first login after 
> migration notices the folder structure has changed & automagically 
> redownloads folders & emails. 

Since you have the migration namespace, that should keep the clients
that have prefix=INBOX. in their configuration working like they did
before. But yeah, if the client hadn't configured a prefix I guess
they'll redownload.

> However I have noticed some really strange 
> messages in the logs which seems to be related to customers running 
> outlook on macos. When they login after migration they are generating 
> commands like:
> 
> dovecot: imap(xxxx): Mailbox created: INBOX 1 1 1 1 1
> dovecot: imap(xxxx): Mailbox created: INBOX 1 1 1 1 1 1
> dovecot: imap(xxxx): Mailbox created: INBOX 1 1 1 1 1 1 1
> ...
> 
> this goes on a long time and we've not yet found a solution other than 
> delete the imap config on their outlook and reconfigure. Does anyone 
> have any idea why this might be happening, 

No idea.

> or if there is a way we can 
> somehow have old namespaces for old customers, new namespaces for new 
> customers (we are using sql login code so should be possible to do 
> something like this in theory I think?)

See the bottom of http://wiki2.dovecot.org/PostLoginScripting on how to
modify namespaces in a post-login script. You can then have your
user_query return "old_namespace" field and based on that you either
modify the namespaces or don't.