Starting with version 1.5.7, we have added a very simple landing page, you can see it at http://demo.MailBul.com/.
This page can be edited by copying the file apps/frontend/views/site/index.php into apps/frontend/views/site/index-custom.php and then change it as you see fit.
Of course, you can disable this landing page at anytime, from Backend > Settings > Common.