I have no log but i think that mails are not scanned, attachements and
virus pass through my stmp server. The only thing i have is message
frozen, but i don't know which message are frozen.
I have that too:
2005-03-01 11:30:37 1D64e2-0005gK-Bt == /dev/null <system-filter>
routing defer (-1): system_filter_file_transport is unset