When sending emails from Forums, content is displayed without theme's CSS rules and is in discrementedly aligned according to the email client language preferences.

Mixed language content is displayed fully aligned to one direction or the other. While each paragraph should be aligned according the its language.

I suggest, that the directionality and text alignment buttons are preset according to the course language when TinyMCE initiate.

Please try to set default direction and text alignment to each paragraph before starting to type according to current language, without clicking the RTL/LTR and Text-Alignment button on the TinyMCE toolbar