#
# To configure Postfix
#

Add to your postfix master.cf:

tumgreyspf  unix  -       n       n       -       -       spawn
  user=%%TUMGREYSPF_USER%% argv=%%PYTHON_CMD%% %%PREFIX%%/bin/tumgreyspf
      
Next, main.cf must be configured so that "smtpd_sender_restrictions"
includes a call to the tumgreyspf policy filter.  If you already have
a "smtpd_sender_restrictions" line(s), you can add the following line
anywhere after the line which reads "reject_unauth_destination".
         
check_policy_service unix:private/tumgreyspf
         
WARNING: It's very important that you have
"reject_unauth_destination" before the "check_policy_service".  If
you do not, your system may be an open relay.
         
So, for example, a minimal "smtpd_sender_restrictions" may look like:

smtpd_sender_restrictions = reject_unauth_destination,
                            check_policy_service unix:private/tumgreyspf

You will also need to have a line in the main.cf which reads:

tumgreyspf_time_limit = 3600

Please consult the postfix documentation for more information on
these and other settings you may wish to have in the
"smtpd_recipient_restrictions" configuration.