Hi,
Thanks for your feedback ; I created a ticket in our TODO list in order to improve the language management in the administrator emails.
HikaShop currently load the user language when you send an email from the backend ; but the inverse is not done (an admin email from the front-end).
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.