Problem with German words encoded into email sent from ERPNext

When I use German version and tried to send email with this subject “Rechnung für die”,
I received email with subject like this

@SwitsolAG May I know which email client you are using to check emails?

Thanks for your answer, we use Outlook for Mac

please still need help

@SwitsolAG

looks like an encoding error what encoding is set in Outlook?

maybe that helps

https://answers.microsoft.com/en-us/msoffice/forum/msoffice_outlook-mso_other/where-is-view-encoding-option/add497a1-f455-4f36-8651-06cbddb1df4f