Created attachment 161008 [details]
Screenshot depicting formatting making text harder to read

SUMMARY

For plaintext emails, KMail applies Markdown-esque formatting to text surrounded by at least **, --, and __ characters. The -- characters in particular are problematic for technical discussion, as they create a strikethrough effect. This makes it hard to read text like this: sockstat -u | grep /tmp/ssh-

STEPS TO REPRODUCE
1. Open email using formatting characters listed above
2. Notice how it changes the appearance of the message in a way that makes it harder to read
3. Observe there's no preference to disable this

OBSERVED RESULT
Commandline text (and other text using these characters for purposes other than formatting) is harder to read, but there's no preference to disable this

EXPECTED RESULT
A preference is added which supports toggling whether to enable this formatting. Alternately, removing the formatting feature altogether would be acceptable as well; part of the point of plain text email is that it's not handled specially and is presented as-is.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.27.7
KDE Frameworks Version: 5.108.0
Qt Version: 5.15.10

ADDITIONAL INFORMATION
The email screenshot in the attachments is from the public arch-general@lists.archlinux.org mailing list.

The Version field on the bug submission form doesn't let me select the version I'm using; it only goes up to 5.23.90.