email software/standards/... link collection ...

postfix basics

http://www.postfix.org/basic.html
http://www.postfix.org/docs.html

virtual domains

http://www.freebsddiary.org/postfix.php
http://www.postfix.org/virtual.5.html
http://jamm.sourceforge.net/howto/single-html/mailserver.html
http://www.pc9.org/guides/postfix_virtual.html