We use OST with three languages activated. When the user selects another language as default set (German), the initial reply emails on a new ticket are always in German. It seems the language setting is not passed in open.php?
Anyway, we would expect that when a user selects a different language on the ticket submit page (e.g. French) that the emails confirming the new ticket are in French too and not the default set language (German).
We solve this by having all languages in the ticket confirm email, but that is not ideal. Also, we need to manually push the ticket into a language department, as otherwise the user receives all emails in the default language (German) and not the language he selected in the user interface.
Any ideas are appreciated here.