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http://www.tummy.com/Products/vpostmaster/recipes/dovecotsasl.html - Syrus vs Dovecot
http://articles.slicehost.com/2010/3/1/barebones-postfix-install-for-ubuntu - Slicehost instructions on postfix
http://cloudservers.rackspacecloud.com/index.php/Postfix_-_Basic_Settings_in_main.cf - Rackspace instructions on postfix, the Slicehost actually seems better