For more clarity I also attach the content of "/etc/dovecot/conf.d/15-mailboxes.conf"

# mailbox Junk { # special_use = \Junk # } # mailbox Trash { # special_use = \Trash # } mailbox INBOX/Junk { auto = subscribe special_use = \Junk } mailbox INBOX/Trash { auto = subscribe special_use = \Trash }

Date: Mon, 24 Jul 2017 18:06:29 +0200 From: Christian Kivalo <ml+dovecot@valo.at>

Please also provide your doveconf -n

Here my Dovecot configuration (I've commented out "mailbox Junk" and "mailbox Trash" above)

# 2.2.13: /etc/dovecot/dovecot.conf # OS: Linux 3.16.0-4-amd64 x86_64 Debian 8.5 ext4 auth_mechanisms = plain login cram-md5 mail_location = maildir:/var/vmail/%d/%n/Maildir mail_plugins = acl managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox INBOX/Junk { auto = subscribe special_use = \Junk } mailbox INBOX/Trash { auto = subscribe special_use = \Trash } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { args = /etc/dovecot/dovecot-sql.conf.ext driver = sql } plugin { acl = vfile:/etc/dovecot/dovecot-acl sieve = ~/.dovecot.sieve sieve_after = /etc/dovecot/sieve-after sieve_dir = ~/sieve } protocols = " imap lmtp sieve pop3" service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } ssl_cert = </etc/letsencrypt/live/server.sio4.org/fullchain.pem ssl_cipher_list = ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA ssl_dh_parameters_length = 2048 ssl_key = </etc/letsencrypt/live/server.sio4.org/privkey.pem ssl_prefer_server_ciphers = yes userdb { args = uid=vmail gid=vmail home=/var/vmail/%d/%n driver = static } protocol imap { mail_plugins = acl imap_acl mail_log notify } protocol lmtp { mail_plugins = acl sieve }

Many thanks Christian!