These are my errors:

Warning: main(../src/validate.php) [function.main]: failed to open stream: No such file or directory in /stuff/mirror/webmail/plugins/serversidefilter/options.php on line 35

Warning: main() [function.include]: Failed opening '../src/validate.php' for inclusion (include_path='.:') in /stuff/mirror/webmail/plugins/serversidefilter/options.php on line 35

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /stuff/mirror/webmail/plugins/serversidefilter/options.php:35) in /stuff/mirror/webmail/functions/global.php on line 375

Warning: main(../src/load_prefs.php) [function.main]: failed to open stream: No such file or directory in /stuff/mirror/webmail/plugins/serversidefilter/options.php on line 38

Warning: main() [function.include]: Failed opening '../src/load_prefs.php' for inclusion (include_path='.:') in /stuff/mirror/webmail/plugins/serversidefilter/options.php on line 38

Fatal error: Call to undefined function: set_up_language() in /stuff/mirror/webmail/functions/imap_general.php on line 570

This is my mailfilter

SHELL="/bin/sh"

import EXT
import HOST

VHOME=`pwd`

##
#  title:  mailfilter-user
#  author: Matt Simerson
#  version 2.0
#  http://www.tnpi.biz/internet/mail/toaster/etc/mailfilter-user
#
#  Usage: Install this file in ./Maildir/mailfilter
#  Call it via a .qmail file with "| maildrop mailfilter"
#
#  After your satisifed that it's working properly, comment out all
#  the lines that start with "log"
##

logfile "/dev/stdout"
#VERBOSE="5"

log "====  BEGIN maildrop processing for $EXT@$HOST ==="

##
# Comment out this section if you run SpamAssassin via qmailscanner
# Spamassassin is slow enough, no point in doubling your expense
#
# Note that if you want to pass a message larger than 250k to spamd
# and have it processed, you'll need to also set spamc -s. See the
# spamc man page for more details.
##
#
#exception {
#       if ( $SIZE < 256000 ) # Filter if message is less 250k
#       {
#               log "  running message through spamc"
#               exception {
#                       xfilter '/usr/local/bin/spamc -u "$EXT@$HOST"'
#               }
#       }
#}
#
##
# Include any rules set up for the user - this gives the
#   administrator a way to override the sitewide mailfilter file
#
#   this is also the "suggested" way to set individual values
#   for maildrop such as quota.
##
`test -r ./.mailfilter`
if( $RETURNCODE == 0 )
{
        log "  including $VHOME/.mailfilter"
        exception {
                include ./.mailfilter
        }
}

##
# create the maildirsize file if it doesn't already exist
# (could also be done via "deliverquota user@dom.com 10MS,1000C)
##
`test -e ./Maildir/maildirsize`
if( $RETURNCODE == 1)
{
        log "  creating $VHOME/Maildir/maildirsize for quotas"
        `/usr/local/vpopmail/bin/vuserinfo -Q $EXT@$HOST`

        `test -s "./Maildir/maildirsize"`
        if ( $RETURNCODE == 0 )
        {
                `/usr/sbin/chown vpopmail:vchkpw $VHOME/Maildir/maildirsize`
                `/bin/chmod 640 $VHOME/Maildir/maildirsize`
        }
}

# Set MAILDIRQUOTA. If this isn't set, maildrop and deliverquota
# will not enforce quotas for message delivery.
#
# I find this much easier than creating yet another config file
# to store this in. This way, any time the quota is changed in
# vpopmail, it'll get noticed by maildrop immediately.
##

`test -s "./Maildir/maildirsize"`
if ( $RETURNCODE == 0 )
{
        MAILDIRQUOTA=`/usr/bin/head -n1 $VHOME/Maildir/maildirsize`
}

##
# The message should be tagged, so let's bag it.
##
if ( /^X-Spam-Status: *Yes/)
{
        `test -d ./Maildir/.Spam`
        if( $RETURNCODE == 1 )
        {
                log "  creating $VHOME/Maildir/.Spam "
                `maildirmake -f Spam ./Maildir`
                `/usr/local/sbin/subscribeIMAP.sh Spam $VHOME`
        }

        log "  SPAM: attempting quota delivery to $VHOME/Maildir/.Spam"
        exception {
                xfilter "/usr/local/bin/deliverquota ./Maildir/.Spam"
        }

        if( $RETURNCODE == 77)
        {
                log "  QUOTA FAILURE: bouncesaying '$EXT@$HOST is over quota'"
                to "|/var/qmail/bin/bouncesaying '$EXT@$HOST is over quota'"
        }

        log "=== END ===  success"
        exit
}
log "  message is clean"

##
# Include any other rules that the user might have from
# sqwebmail or other compatible program
##

`test -r ./Maildir/.mailfilter`
if( $RETURNCODE == 0 )
{
        log "  including $VHOME/Maildir/.mailfilter"
        exception {
                include ./Maildir/.mailfilter
        }
}

exception {
        log     "  quota enabled delivery to $VHOME/Maildir"
        xfilter "/usr/local/bin/deliverquota ./Maildir"
}

##
# check to make sure the message was delivered
# returncode 77 means that out maildir was overquota - bounce mail
##
if( $RETURNCODE == 77)
{
        log "  BOUNCED: bouncesaying '$EXT@$HOST is over quota'"
        to "|/var/qmail/bin/bouncesaying '$EXT@$HOST is over quota'"
}

log "=== END === success"