Hi, I am customising templates for sending automatic e-mails to customers when they open a new ticket.

Our customers have different native languages. So I would like the automatic e-mail to be in the right language. However, I cannot access the information from the velocity template.
I have tried to access the class UserPreferencesManager but it is not accessible from velocity. I also tried to search for the class with $content but it is also not accessible from velocity. In UserPropertyManager I didn't find a language property.
Does anyone know a way to do this?