The default MTA in SLES9 is Postfix while the default IMAPD is cyrus. Hence, I start to figure out how to use them. By the way, it is really hard to get some good, and in-depth documentation.
Finally, the best document for Cyrus is the official documentation. Besides, I have found two HOW-TO on configuring Postfix + Cyrus on FreeBSD. (But IMO, both of them fail to explain the stuff, anyway, still a good source for me).
After all, I've managed to do it. The following is my notes of Postfix + Cyrus + Virtual Host on SLES-9
