Installation:

# wget http://www.bertera.it/software/apolicy/apolicy-0.5-greylist.tgz
# apt-get install python2.3-pysqlite2
# tar xzvf apolicy-0.5-greylist.tgz
# cp apolicy-0.5/src/apolicy.py /usr/lib/postfix
# python setup.py install
# echo "apolicy  unix - n n - - spawn" >> /etc/postfix/master.cf
# echo "   user=nobody argv=/usr/lib/postfix/apolicy.py" >> /etc/postfix/master.cf

The configuration file is loaded by default from /etc/apolicy/apolicy.conf, you can use -c parameter to change and point where your configuration file is. It is possible to debug your configuration using the parameter -d, it will send a lot of output to syslog mail facility

Finally, add to your main.cf:
smtpd_recipient_restrictions =
         reject_unlisted_recipient
         ...
         reject_unauth_destination 
         check_policy_service unix:private/apolicy

For the size acl works, apolicy need to be called this way:
smtpd_end_of_data_restrictions = check_policy_service unix:private/apolicy 

# /etc/init.d/postfix restart

Example of /etc/apolicy/apolicy.conf:

# main configuration of apolicy
[main]
# Parameter: 'policy_engine'
# Sets the engine that will be used to load the policy.
policy_engine = file

# configuration of the 'file' engine
[file]
# Parameter: 'path'
# Sets the path for the file that contains the policy configuration.
path = /opt/apolicy-0.5/policy.conf

[greylist]
# time in minutes of greylisting
time = 5
# lifetime in minutes of any entry in graylist db
# 10 days
lifetime = 72000
# greylist sqlite db
db = /tmp/greylist.db


ACL Examples:

# disabling greylist for a sender
acl pierto sender pietro@bertera.it
no_greylist pietro


# disabling greylist for a domain:
acl bertera sender @bertera.it
no_greylist bertera


# enabling greylisting if sender ip is found in one of rbl list:
acl any sender (.*)
acl rbl1 rbl dynablock.njabl.org
acl rbl2 rbl dul.dnsbl.sorbs.net
acl rbl3 rbl cbl.abuseat.org
acl rbl4 rbl sbl-xbl.spamhaus.org
acl rbl5 rbl bl.spamcop.net
action dunno DUNNO
access any dunno
no_greylist !rbl1 !rbl2 !rbl3 !rbl4 !rbl5


# enabling greylisting if sender ip is found in all rbl list:
acl any sender (.*)
acl rbl1 rbl dynablock.njabl.org
acl rbl2 rbl dul.dnsbl.sorbs.net
acl rbl3 rbl cbl.abuseat.org
acl rbl4 rbl sbl-xbl.spamhaus.org
acl rbl5 rbl bl.spamcop.net
action dunno DUNNO
access any dunno
no_greylist !rbl1 
no_greylist !rbl2 
no_greylist !rbl3
no_greylist !rbl4 
no_greylist !rbl5

------------------------------------------------------------------------
Manipulating greylist database:

bertera:/opt/apolicy-0.5# ./src/GreylistDB/greylistdb.py -h
./src/GreylistDB/greylistdb.py -c policy.conf 
        [-a ip:sender:recipient]  add a greylist entry
        [-r ip:sender:recipient] remove a greylist entry
        [-s] show greylist database
        [-d] clear grelist db
        [-t ip:sender:recipient] touch a entry timestamp
        [-g ip:sender:recipient] get a entry
        [-e  timesec] get expired entry

The output format is:sender IP  [sender => recipient]   last seen unix time     -       state


Showing greylist full database:
bertera:/opt/apolicy-0.5# ./src/GreylistDB/greylistdb.py -c apolicy.conf -s
82.54.116.40    [root@localhost.localdomain     =>      pietro@bertera.it]      1165657808      --      true
87.242.24.203   [vickieaspandora@ppionline.org  =>      pietro@bertera.it]      1165657613      --      false
59.184.61.72    [keycapmortgage.com@samplerealaccess.com        =>      bug@bertera.it] 1165658086      --      false
211.209.74.214  [sheehanycoraelide@angeles-designs.com  =>      pietro@bertera.it]      1165659235      --      false
75.39.167.134   [hotels@link2hotels.com =>      info@bertera.it]        1165659553      --      false
82.61.176.95    [dupontdev@vanderwyk.com        =>      info@bertera.it]        1165660434      --      false

Sat, 09 Dec 2006  Pietro Bertera <pietro@bertera.it>