thanks for fast replies.
i prefer not using ISPConfig because i want to learn how to administrate linux servers and i'm gentoo-guy so i think that you will never have unknow problems if you'll do everything "by hands"
i'd like to use that postfix+mysql_courier+blahblahblah tutorial but it's for debian and apt-get for fedora doesnt have such packets (i use 3 sources, provided in fc4 perfect setup howto) :/
anyway, i'll try to follow that tutorial tomorrow. or use this one: