dovecot.conf for debian 9 with CLucene FTS

dovecot.conf

protocols = imap pop3
auth_mechanisms = plain login
auth_cache_size = 24 M
auth_cache_ttl = 18 hours
disable_plaintext_auth = no
listen = *,[::]
log_timestamp = "%Y-%m-%d %H:%M:%S "
log_path = /var/log/dovecot.log
login_greeting = encrypted ready.
postmaster_address = julius@encrypted.net

ssl_protocols = !SSLv3
ssl_cert = </etc/postfix/smtpd.cert
ssl_key = </etc/postfix/smtpd.key

# see https://wiki.dovecot.org/MailLocation/LocalDisk
mail_fsync = never
mail_temp_dir = /ramm/dovecot

mail_max_userip_connections = 500
mail_privileged_group = vmail
mail_plugins = " fts fts_lucene"
mailbox_idle_check_interval = 59 secs
mailbox_list_index = yes
maildir_very_dirty_syncs = yes

passdb {
  args = /etc/dovecot/dovecot-sql.conf
  driver = sql
}

plugin {
  fts = lucene
  fts_autoindex = yes
  fts_autoindex_max_recent_msgs = 60
  fts_index_timeout = 60
  fts_lucene = whitespace_chars=@. normalize no_snowball
  sieve = /var/vmail/%d/%n/.sieve
  sieve_max_redirects = 25
}

service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
  unix_listener auth-userdb {
    group = vmail
    mode = 0600
    user = vmail
  }
  user = root
}

service imap-login {
  process_min_avail = 6
  service_count = 64
  vsz_limit = 256 M
  client_limit = 1000
  process_limit = 512
  }

service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
    group = postfix
    mode = 0600
    user = postfix
  }
}

userdb {
  driver = prefetch
}
userdb {
  args = /etc/dovecot/dovecot-sql.conf
  driver = sql
}

protocol pop3 {
  pop3_uidl_format = %08Xu%08Xv
}

protocol lda {
  mail_fsync = optimized
  mail_plugins = sieve
  postmaster_address = julius@encrypted.net
}

protocol lmtp {
  mail_fsync = optimized
  mail_plugins = sieve
  postmaster_address = julius@encrypted.net
}

cron.monthly that cleans up people's Junk and Trash

#!/bin/sh
doveadm expunge -A mailbox Junk savedbefore 90d
doveadm expunge -A mailbox Trash savedbefore 660d
doveadm force-resync -A '*'
exit 0

kills Spam older than 90 days, and Trash older than ~2 years..