[Dovecot] .dovecot.sieve not being read

[ding dong]

Mail seems to be delivered to INBOX without reading what is in
.dovecot.sieve

# cat /home/vmail/user at example.com/.dovecot.sieve
if exists "From" {
  discard;
  stop;
}

# ls -alh /home/vmail/user at example.com/.dovecot.sieve
-rw-r--r--  1 vmail  vmail    41B Oct 29 01:26 .dovecot.sieve

# tail /var/log/dovecot-deliver.log
deliver(user at example.com): Oct 29 01:33:14 Info: msgid=<
47253857.20500 at example.com>: saved mail to INBOX

# tail /var/log/maillog
Oct 29 01:33:14 freebsdserver1 dovecot: auth-worker(default): sql(
user at example.com): SELECT maildir AS home, uid AS uid, gid AS gid FROM
virtual_mailboxes WHERE user = 'user at example.com' AND enabled = TRUE LIMIT 1
Oct 29 01:33:14 freebsdserver1 dovecot: auth(default): master out:
USER       1       user at example.com
home=user at example.com/uid=1002        gid=1002
Oct 29 01:33:14 freebsdserver1 postfix/pipe[25035]: 8CB9F1CC2A: to=<
user at example.com>, relay=dovecot, delay=0.08, delays=0.04/0.02/0/0.03, dsn=
2.0.0, status=sent (delivered via dovecot service)

# dovecot --version
1.0.5

# dovecot -n
# 1.0.5: /usr/local/etc/dovecot.conf
login_dir: /var/run/dovecot/login
login_executable: /usr/local/libexec/dovecot/imap-login
verbose_proctitle: yes
first_valid_gid: 0
mail_extra_groups: vmail
mail_location: maildir:/home/vmail/%h
imap_client_workarounds: delay-newmail outlook-idle netscape-eoh
tb-extra-mailbox-sep
auth default:
  mechanisms: plain login
  verbose: yes
  debug: yes
  passdb:
    driver: pam
  passdb:
    driver: sql
    args: /usr/local/etc/dovecot-sql.conf
  userdb:
    driver: passwd
  userdb:
    driver: sql
    args: /usr/local/etc/dovecot-sql.conf
  socket:
    type: listen
    client:
      path: /var/spool/postfix/private/auth
      mode: 432
      user: postfix
      group: postfix
    master:
      path: /var/run/dovecot/auth-master
      mode: 384
      user: vmail
      group: vmail