Here is my "dovecot -n": # 2.3.0.1 (ffd8a29): /etc/dovecot/dovecot.conf # Pigeonhole version 0.5.0.1 (d33dca2) # OS: Linux 4.4.0-116-generic x86_64 Ubuntu 16.04.4 LTS auth_debug = yes auth_username_format = %n auth_verbose = yes hostname = volker-wysk.de log_path = /var/log/dovecot.log mail_debug = yes mail_location = mdbox:~/lib/Dovecot-Mail 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 index ihave duplicate mime foreverypart extracttext imapsieve vnd.dovecot.imapsieve namespace inbox { inbox = yes location mailbox Drafts { special_use = \Drafts } mailbox Entw?rfe { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Papierkorb { special_use = \Trash } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } mailbox "Versendete Nachrichten" { special_use = \Sent } prefix separator = . } passdb { driver = pam } plugin { imapsieve_mailbox1_before file:/usr/lib/dovecot/sieve/report-spam.sieve imapsieve_mailbox1_causes = COPY imapsieve_mailbox1_name = Spam imapsieve_mailbox2_before file:/usr/lib/dovecot/sieve/report-ham.sieve imapsieve_mailbox2_causes = COPY imapsieve_mailbox2_from = Spam imapsieve_mailbox2_name = * sieve = ~/.dovecot.sieve sieve_dir = ~/lib/Sieve sieve_global_extensions = +vnd.dovecot.pipe +vnd.dovecot.environment sieve_pipe_bin_dir = /usr/lib/dovecot/sieve sieve_plugins = sieve_imapsieve sieve_extprograms } postmaster_address = post at volker-wysk.de protocols = imap lmtp sieve ssl = required ssl_cert = </etc/ssl/certs/dovecot.pem ssl_dh = # hidden, use -P to show it ssl_key = # hidden, use -P to show it userdb { driver = passwd } protocol lmtp { mail_plugins = " sieve mail_log notify" } protocol lda { mail_plugins = " sieve" } protocol imap { mail_max_userip_connections = 50 mail_plugins = " imap_sieve" }