mailbox_list_layout = fs must appear explicitly in the config file even though it's the default value used according to https://doc.dovecot.org/2.4.1/core/config/mail_location.html#mailbox_list_layout If not set the folders will appear as .Drafts .Junk .Sent .Trash in the user's Mail directory instead of Drafts Junk Sent and Trash.pull/352/head