Wie man externe E-Mail-Adressen hervorhebt

The macOS email client has a very interesting feature: you can have all emails that do not come from your domain highlighted.

For example, if your email comes from the @myenterprise.com domain, any emails that come from another domain will be highlighted (in the From, To, Cc, and Bcc fields).

Here is a link that explains what I want to do : https://www.developsec.com/2018/10/05/app…mail-addresses/

Is it possible to change some of the code in BetterBird to achieve this behavior?

Thank you.

I created it: https://bugzilla.mozilla.org/show_bug.cgi?id=1859763

Regards.