I recently did a Postfix installation for Electrocaine on a Linode VPS. And I must admit, I ran into some weird problems when trying to follow the tutorial on linode library, http://library.linode.com/email/postfix/postfix-courier-mysql-debian-5-lenny .
My best advice to you when you are editing the config files with vim, make sure that to change lines you hit shift+enter instead of enter to make it a Line Feed.
Configuration was quite an easy task : )
