On Sep 5, 2025, at 14:54, Aki Tuomi via dovecot <dovecot@dovecot.org> wrote:
You can try to make it work *but* it requires that everyone has the *same* root folder for mails (mail_path). If you use something like mdbox/ and maildir/, it's not going to be possible to make it work. So use something like
mail/.
We store mailbox format and folder name in SQL like below:
MariaDB [vmail]> select username,mailboxformat,mailboxfolder from mailbox \G
*************************** 1. row ***************************
username: maildir@a.io
mailboxformat: maildir
mailboxfolder: Maildir
*************************** 2. row ***************************
username: mdbox@a.io
mailboxformat: mdbox
mailboxfolder: mdbox
I also updated userdb to query and return them, then use them in
namespace shared {} like %{userdb:mailboxformat}, %{userdb:mailboxfolder},
doesn't work either.
Once everyone has same mail root folder, you can try to use mail_driver=auto in namespace shared. Don't use this for namespace inbox, because it will behave unexpectedly (for you) if the mailbox does not exist.
You will run into exact same issues with 2.3 and 2.4. The problem is that the shared namespace cannot know what the target user is using for mail path if you don't use the same path.
Doc mentions variables like %{owner_home}, %{owner_user}, will it
work perfectly if Dovecot exports owner's mail_driver and mail_path
with variables like %{owner_mail_driver}, %{owner_mail_path}?