Plain text view of E-Mail does not display lot of characters correctly (wrong encoding?)

[fridlmue]

Describe the bug
Received E-Mail contend below the AI-Summery has issues with the encoding. Most special characters are not shown correctly.

To Reproduce
Steps to reproduce the behavior:

1. Send E-Mail with special characters like äöüß
2. Receive it in the Mind2 Inbox
3. Click on the Mail to view the AI Summary and Content
   Expected behavior
   Content is shown wit correct encoding and display of special characters.

Screenshots

Environment(please complete the following information):

• OS: Linux/KDE
• Browser : Firefox 137
• Version: Venho 0.4.2

Additional context
Original Mail-Body:

Test, on how some Characters will appear:
This is sent Plain Text
aeiou
äöü
ß