1. Install Dovecot Pigeonhole with Sieve protocol enabled Local Delivery Agent (LDA),
    enable ManageSieve server, specify Sieve rule locations, create Sieve files and set
    permissions, and restart Dovecot
    1. # yum install dovecot-pigeonhole
    2. # vi /etc/dovecot/local.conf (Add)
      1. mail_location = maildir:~/Maildir
      2. protocols = $protocols sieve
      3. plugin {
              sieve = ~/.dovecot.sieve
              sieve_dir = ~/.sieve
        }
      4. service managesieve-login {
              inet_listener sieve {
              port = 4190
              }
        }
      5. protocol lda {
              mail_plugins = $mail_plugins sieve
              .
              .
              .
        }
        
    3. # cd /home/vpopmail/domains/domain.tld/user
    4. # mkdir .sieve
    5. # touch .sieve/user.sieve
    6. # ln -s .sieve/user.sieve .dovecot.sieve
    7. # chown -R vpopmail:vchkpw .sieve
    8. # chown vpopmail:vchkpw .dovecot.sieve
    9. # chmod 700 .sieve
    10. Add Sieve rules to .sieve/user.sieve
  2. Enable Dovecot LDA formatted logging
    1. # vi /etc/dovecot/local.conf (Add)
    2.       protocol lda {
               deliver_log_format = From:<%f>-<%e> :: Subject:<%s> :: Status:<%$> :: MsgID:<%m> :: Size<%p> :: vSize<%w>
               log_path = /var/log/dovecot-lda/dovecot-lda-errors.log
               info_log_path = /var/log/dovecot-lda/dovecot-lda.log
            }
      
    3. # mkdir /var/log/dovecot-lda
    4. # chmod 770 /var/log/dovecot-lda
    5. # chown vpopmail:vchkpw /var/log/dovecot-lda
    6. # touch /etc/logrotate.d/dovecot-lda (Add settings)
  3. Enable Dovecot LDA for QMT
    1. # vi /home/vpopmail/domains/yourdomain.tld/.qmail-default (Edit)
      1. |/home/vpopmail/bin/vdelivermail '' bounce-no-mailbox (Remove)
      2. |/var/qmail/bin/preline -f /usr/libexec/dovecot/deliver -d $EXT@$USER -o postmaster_address=postmaster@yourdomain.tld (Add)
  4. # systemctl restart dovecot