Greetings, I think I have diabled the DNS and URI lookups and Razor/Pyzor/DCC, and it still takes around 1x seconds to scan one email, but we have a little power supply problem at this moment so I cannot check the configuration file, I'll check it later. I still think it may be caused by the UTF-8 locale. Since the load of that mail server is not high, so may be I just let it there for a moment if I cannot find where the "problem" is.
Regards, Deephay