configurations/Dovecot/conf.d/20-lmtp.conf

service lmtp {
   inet_listener lmtp {
      address = 127.0.0.1 ::1
      port = 24
   }

   unix_listener lmtp {
      #mode = 0666
   }
}

protocol lmtp {
  info_log_path = /var/log/mail/lmtp.log
  mail_plugins = "sieve"
}