Forwarding x unscanned messages / slow scanning

[Matthias Kellermann]

Hi folks,

i've a running MailScanner system with Postfix.

When the queue runs full (about 250 messages) I get lots of messages 
like this from MailScanner:

Apr 20 12:40:39 server check[23677]: Batch completed at 895 bytes per 
second (35672 / 39)
Apr 20 12:40:39 server check[23677]: Batch (3 messages) processed in 
39.83 seconds
Apr 20 12:40:39 server check[23677]: New Batch: Found 195 messages waiting
Apr 20 12:40:39 server check[23677]: New Batch: Forwarding 1 unscanned 
messages, 1916 bytes
Apr 20 12:40:39 server check[23677]: New Batch: Scanning 3 messages, 
108887 bytes

It needs a long time (about 30minutes) to clear the queue because 
MailScanner is too slow.

There are lots of messages in the queue that shouldn't be scanned 
because I've setup a own scanning rule (scan.messages.rules). So I think 
this messages should get processed very fast by MailScanner, but they 
aren't.

Here are my settings in the MailScanner.conf file:

Max Unscanned Bytes Per Scan = 10000
Max Unsafe Bytes Per Scan = 50000
Max Unscanned Messages Per Scan = 10
Max Unsafe Messages Per Scan = 10

Maximal MailScanner children:
Max Children = 4

I've got played with the Unscanned-/Unsafe-settings with no success. Can 
you give me any hints to speed up things?

Thanks in advance.

Best Regards
Matthias