Not solved, but found the reason of the problem:Obviously, the plugin "listescape" breaks the sharing of the INBOX of user <owner> as "Shared/<owner>" for another user.
At least with usernames containing a dot "." as in "[email protected]", which are used as the name of the filesystem Maildir home directory. (IMAP separator "/".) When using this plugin, a "\Noselect" tag is added then to the output of the response to the IMAP command 'list "" "Shared/[email protected]"'.
Best Regards, R.Koerner
