linode has nice guides...e.g. https://library.linode.com/email/postfix/dovecot-mysql-debian-6-squeeze https://library.linode.com/email/postfix/dovecot-mysql-deb

linode has nice guides...e.g. https://library.linode.com/email/postfix/dovecot-mysql-debian-6-squeeze https://library.linode.com/email/postfix/dovecot-mysql-debia... though for postfix, having something like postfixadmin makes it nicer.. or perhaps something instant like http://www.xeams.com/ http://www.xeams.com/ will do..