Amavis stalling on large emails

[via amavis-users]

Using postfix, amavis, spamd, clamav.

I recently migrated to a new server.  Configuration is the same but 
latest versions of all software.  Postfix allows 50MB emails.  Amavais 
sa_body_size_limit is 200*1024.

I have some 4 stuck in the postfix queue, timing out (1800 sec timeout). 
  These emails are all > 30MB.

What should I be looking for?  Obviously it shouldn't be passing to SA 
at that size.  Could clamd be taking that long?  If so, how do I address 
that?