[Mailman-Users] Bounces not being detected

[Peter Fraser]

Hi AllI have mailman-2.1.17 running on FreeBSD 9.1 along with postfix-2.11.0,1
I noticed that bad email addresses were not being cleared out so I downloaded get_bounce_info.py,saved it and ran it. No bounce info was displayed.I checked the postfix logs and the bounce info was there. A bit from the logs is below:
status=bounced (host bla bla .com[x.x.x.x] said: 550 5.7.1 No mailbox found (in reply to RCPT TO command))
Shouldn't mailman detect these bounces?
Does mailman detect from the smtp logs or some other method?
Thanks for any help received.