1. Bookings via booking engine
When a guest books on mybookings, they can select the language in the right upper corner of the booking engine. This determines the language of the email confirmation.
Please make sure you have translated all email templates to relevant languages. To do that please see how to customize email templates.
To limit the languages available on the booking engine go to manage area > mybookings settings and untick unnecessary languages.
2. Direct (dashboard) bookings
When a direct reservation is created language of the email confirmation is determend by country entered on the reservation details.
If country isn't entered, email will be sent in the language of the myfrontdesk application.