pop3 mail not deleting.

[Bob Meader]

I have a bit of odd pop3 problem.  Just one of
my email clients is reporting a problem with
Outlook and pop3.  Spefically he has sent
Outlook to leave mail on the server up to 5 days.
The problem is after several weeks mail older
than 5 days is no longer deleted from server.
In order to delete mail I have hime momentary set
Outlook not save mail on server.  After the mail
is deleted and the option to leave 5 days
of mail on server is turned back on,everything
works OK for several weeks. Anyone else
have same problem?

I am using cyrus v2.1.11 running on NetBSD 1.6
installed via "pkg" collection.

================= cyrus.conf ====================================
# standard standalone server implementation

START {
  # do not delete this entry!
  recover       cmd="ctl_cyrusdb -r"

  # this is only necessary if using idled for IMAP IDLE
#  idled                cmd="idled"
}

# UNIX sockets start with a slash and are put into /var/imap/socket
SERVICES {
  # add or remove based on preferences
  imap          cmd="imapd" listen="imap" prefork=0
  imaps         cmd="imapd -s" listen="imaps" prefork=0
  pop3          cmd="pop3d" listen="pop3" prefork=0
  pop3s         cmd="pop3d -s" listen="pop3s" prefork=0
  sieve         cmd="timsieved" listen="sieve" prefork=0

  # at least one LMTP is required for delivery
#  lmtp         cmd="lmtpd" listen="lmtp" prefork=0
  lmtpunix      cmd="lmtpd" listen="/var/imap/socket/lmtp" prefork=0

  # this is only necessary if using notifications
#  notify       cmd="notifyd" listen="/var/imap/socket/notify" proto="udp"
prefork=1
}

EVENTS {
  # this is required
  checkpoint    cmd="ctl_cyrusdb -c" period=30

  # this is only necessary if using duplicate delivery suppression
  delprune      cmd="ctl_deliver -E 3" at=0400

  # this is only necessary if caching TLS sessions
  tlsprune      cmd="tls_prune" at=0400
}
=================imapd.conf=====================================
# $NetBSD: imapd.conf,v 1.1.1.1 2002/10/27 16:08:53 chris Exp $
#
# Cyrus IMAP server configuration file.  Refer to imapd.conf(5) for
# more options.

configdirectory: /var/imap
partition-default: /var/spool/imap
sieveusehomedir: false
hashimapspool: false
sendmail: /usr/sbin/sendmail

admins: cyrus

# Use the saslauthd daemon to verify plaintext passwords.  Please ensure
that
# the saslauthd daemon is running before trying to authenticate.
#
sasl_pwcheck_method: auxprop
tls_cert_file: /var/imap/server.pem
tls_key_file: /var/imap/server.pem