Since mailbox_command = /opt/eset/esets/bin/esets_mda -d "$USER" -- --recipient="$RECIPIENT" --sender="$SENDER" Does not work for me (im using Virtual Domains and dont use this Command "directly") (my command is "mailbox_command = /usr/libexec/dovecot/deliver) I tryed to work around that - I changed in the master.cfg: dovecot unix - n n - - pipe flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${user}@${domain} -m ${exte