(solved) Multilingual Registration Email: Doesn't work

Hi Forum,

I managed to setup a bilingual Drupal 7 page.

All well functioning: All german sites also exist in english.

But the thing: every time someone registers in german, he got an english welcome email. Don’t understand this.

When I looked at the translations at /admin/config/regional/translate/translate, every single email-text exists with its according translation. And at: /admin/config/regional/i18n/variable, in the User emails tab, I checked all fields and saved.

Anyway: if I register, though I got a german welcome message in the browser, the sent email is still english, but should be german.

Did I forget something?

Many thanks for help!

Drupal version: 

Source: https://www.drupal.org/taxonomy/term/22/feed