Order receipt mail uses admin interface language when resend order confirmation.
I think that mail should be send with the language used in the checkout process.
Enable drupal multilingual modules
Add a 2nd language
Order something in English and complete transaction as a guest
You will receive your receipt in English.
Go to commerce order resend receipt as admin in other language.
Same problem with registered users.
Active
2.0
Order
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It's likely this issue predates Contrib.social: some issue and comment data are missing.
I'm adding a related issue where there's a suggestion on how to deal with multi-language stores and e-mail language detection for anonymous and registered users.
Same issue for me.
I think this is not a feature request but a bug.