Change language of Notification Mails for User submitted E-Mails

Currently, Microsoft Defender for Office 365 does not provide direct options to change the language of the admin review emails (like the subject or body text) — they are typically sent in English by default.

However, you could consider customizing the email notifications via PowerShell or using automated workflows (like Logic Apps or Power Automate) to intercept and modify the emails before sending them to customers. Another workaround is to set the preferred language for the user’s mailbox via their Exchange settings, though it doesn't guarantee full language customization for these specific Defender emails.

Hope that helps!