http://www.qmail.org/
http://www.jp.qmail.org/
http://jf.linux.or.jp/JF/JF.html
http://www.geocities.co.jp/SiliconValley-Bay/2440/
http://www.zdnet.co.jp/help/howto/security/special6/index.html
http://slashdot.jp/article.pl?sid=04/01/19/1327259&topic=16&mode=nested
http://www.emaillab.org/djb/index.html
http://www.asahi-net.or.jp/~aa4t-nngk/qmail.html