Copy-Paste of a mail shown in NCmail does not contain the mail's body

[janklostermann]

Steps to reproduce

1. Mark the subject's text and copy it with CTRL+C works.
2. Mark the mail's subject and text and copy it with CTRL+C does NOT work (contains only subject, addresses and NOT the body, even though the body is marked (as blue rectangle).
3. Mark a section in the body and copy it via CTRL+C works (sometimes contains more than marked, e.g. if above the mail there is additional information shown, e.g. about blocked images).
4. Mark a section in the body and copy it via the Context Menu entry "Copy as Markdown" provided from a browser plugin does NOT work (empty). This applies to at least 2 WebClipper browser plugins: Copy As Markdown, Joplin WebClipper.
5. When storing the whole webpage with the browsers CTRL+S (as a workaround) the mail's body is missing.

This applies to Chrome as much as Firefox as browsers.
Apparently all these paths get stuck at the iframe-inclusion of the mail's body, which they don't seem to be able to resolve.

Expected behavior

That all of these approaches provide a possibility to extract the mail's content into another text editor, preferably with formatting, if existing, and also available to browser plugins for converting such content into other formats (like markdown in this case).

Actual behavior

I could not find a way to extract the content of a mail's body to copy it with formatting (as markdown) into another program, as possible with almost every other webbrowser content.

Is this an (intented but annoying) safety feature or a bug / design flaw?

Mail app version

5.1.7

Nextcloud version

31.0.7

Mailserver or service

various

Operating system

Windows

PHP engine version

None

Nextcloud memory caching

No response

Web server

None

Database

None

Additional info

No response