Hi,
unfortunately I found a bug in Dovecot's ACL handling for shared
mailboxes. It turns out Dovecot doesn't enforce lower casing the
privileged username to whom the mailbox should be shared to. This
results in a invalid configuration. Users get confused, since they
passed on a valid email address in their ACL setup.
/usr/local/www/default/mail/test@mydomain.localdomain/maildir/.Spam/dovecot-acl
user=leander@mydomain.localdomain eilrwts
^^ works
/usr/local/www/default/mail/leander@mydomain.localdomain/maildir/dovecot-acl
user=test@mydomain.localdomain eilrwts
^^ works
/usr/local/www/default/mail/test@mydomain.localdomain/maildir/.Drafts/dovecot-acl
user=Leander@MyDomain.LocalDomain eilrwts
^^ Doesn't work
Best regards
Leander Schäfer