EmailAutoDiscover

http://www.andrewyager.com/blog/2008-09-13/outlook-2007-email-autodiscovery-php-server

http://www.winblogs.net/index.php/2012/08/07/autodiscover-with-smartermail-or-any-other-mail-server/

https://github.com/jamesiarmes/php-ews/wiki/Autodiscovery

It is unlikely that autodiscover can be configured without a valid SSL certificate for the domain in the email address. Implementing a mass-hosting version of autodiscover would be prohibitively expensive due to this. It would however be possible to configure it on a per-domain basis provided the SSL certificate is purchased (or a self-signed one is installed on all client machines - Would this work?)