How to enable debug logging in kolab_smtp_access_policy ?

[Geert Janssens]

I'm still hunting the unusually slow performance of mail and calendars 
on our site (which I already asked about before our holidays).

I'm going over several components in the mail sending chain and came 
across
/usr/libexec/postfix/kolab_smtp_access_policy

This appears to be a python script that verifies senders and recipients. 
It has some code for logging its activities.

I'd like to enable debug logging for this tool, but it's unclear to me 
how to do this. Can someone tell me how to do it ?

Thank you,

Geert Janssens