# assuming Slackware Linux
# virtual domains and Maildir format

PATH=/bin:/usr/bin:/usr/local/bin
SHELL=/bin/ksh
DROPPRIVS=yes
VERBOSE=no
LOGFILE=/var/log/procmail.log

MAILDIR=/var/spool/virtual/${ER_DOMAIN}/${ER_USER}/
DEFAULT=/var/spool/virtual/${ER_DOMAIN}/${ER_USER}/

SYSYEAR=`date +%Y`

# grab the year from the last Received header
:0
* $ ^Received:.*for .*; \/(Mon|Tue|Wed|Thu|Fri|Sat|Sun), .+
{
        MFROM_ = $MATCH
        #LOG="MFROM_ = $MFROM_"

        :0
        * MFROM_ ?? ()\/[1-9][0-9][0-9][0-9]
        { YEAR = $MATCH }
        #LOG="YEAR = $YEAR"
}

# deal with sent-mail (Received header is missing)
:0
* ? [[ -z $YEAR ]]
{
        :0
        * $ ^Date: \/(Mon|Tue|Wed|Thu|Fri|Sat|Sun), .+
        {
                MFROM_ = $MATCH
                #LOG="MFROM_ = $MFROM_"

                :0
                * MFROM_ ?? ()\/[1-9][0-9][0-9][0-9]
                { YEAR = $MATCH }
                #LOG="YEAR = $YEAR"
        }
}

# define and do some tests against YEAR
# otherwise you may end up with `.archives..inbox`
:0
* !? [[ $SYSYEAR = $YEAR ]]
{ prefix = .zarchives-${YEAR} }

:0
* ? [[ -z $YEAR ]]
{ prefix = .zarchives-NOYEAR }

# process sent-mail first
:0
* !^Received:
* ^From:.*$ER_USER@$ER_DOMAIN
${prefix}.sent-mail/

:0
* !^Received:
${prefix}.sent-mail-nofrom/


# finish-up
:0
* !^\
(To:.*$ER_USER@$ER_DOMAIN\
|Cc:.*$ER_USER@$ER_DOMAIN)
${prefix}.bcc/

# we need to differenciate older vs. current year inboxes for once (the rest goes to DEFAULT)
#* !? [[ $SYSYEAR = $YEAR ]]

# UNTESTED
:0
* ^\
(To:.*$ER_USER@$ER_DOMAIN\\
|Cc:.*$ER_USER@$ER_DOMAIN\)
${prefix}/