[Mimedefang] spam_assassin_check randomly returns zero points and blank names

[Cliff Hayes]

I don't know how long this has been going on but I just noticed that 
about 1% of emails going through our system are being assigned zero 
points/hits and blank tests/names.  I don't know how to troubleshoot 
this?  Where should I start?  I see no errors and everything appears 
normal.  The system is nowhere near capacity and it's happening on all 
our mx servers.