These newsletters have always been hard to create as regular web HTML is not properly read by web email interfaces and email clients. I thought that the simplest solution would be to use a web page that would serve as a web version of the newsletter and turn it somehow into newsletter HTML.
To fix issues with display of special language characters once and for all
there's a solution: use Unicode UTF-8 everywhere. If everything is set up to use Unicode, you can use mostly every language in your application.
I found a standard Yii app's protected folder structure nearly perfect. With a few simple moves and a little bit change to the code, I managed to bring it to the level, which I found as fully perfect. I want to share my point of view, in case someone would like to use this structure as well.
This article shows one of possible ways to implement menu items (as well as links), which displays a progress / wait dialog and are redirecting browser to destination URL in the same time. This is especially useful, for links or routes that are know to be loaded for a prolonged period of time (i.e. getting a lot of data from database).