To use Seiichiros mail-setup with Ubuntu 10.04 I have to make a couple of changes. I will describe here only these changes. The complete setup can be found on Seiichiros Website.
The Ubuntu 10.04 standard repository doesn't offer a package for dovecot2. Dovecot1 doesn't support lmtp and the antispam plugin has a bug. With use of an additional repository the configurations can be made as described by Seiichiro. I had to made a few adjustments and I integrated support for ClamAV.