On User Creation, send user registration email in his language preference Is there a way to send the welcome message to a new user in his preferred languages ?

As an Administrator of the website, I create all the users with their preferred languages. I Check the button to notify the user when the user is created.
The email is sent correcly but not in the languages that I specify for a particular user.

I already install the I18n module and made the translation between each languages.

Thanks a lot
I think you need to change the way drupal detect the language of the current user.

You can do so by going to /admin/config/regional/language/configure and check "Follow the user's language preference.". You may need to move this option as the first detection method.