https://qmail.jms1.net/dovecot.shtml
http://tumbleweed.org.za/2007/10/03/dovecot-shared-mailboxes-correct-way
https://wikit.firewall-services.com/doku.php/smedev/dovecot
http://wiki.qmailtoaster.com/index.php/Replacing_Courier_IMAP_with_Dovecot_IMAP
http://forum.directadmin.com/showthread.php?t=40809
http://www.zimbra.com/forums/migration/61710-qmail-dovecot-imap-zimbra-migration.html