I've spent last 2 hours with Drupal CAPTCHA module - the default image and math captchas didn't stop any spam user at all - I could see fake users still registering - every few seconds (scary!).
I have uploaded a russian font then and configured the CAPTCHA to use russian letters only (since my site is targeting Russian users) - this has stopped them for now. I'm just saying, that the whole problem isn't trivial and obvious comments (install captcha etc.) aren't really helping here, that's why I asked the specific postfix question here... Have a nice day, sorry for offtopic ramblings Alex
