If you are using Google to search for KMail the first looks like the official KMail page:
KMail - KDE.org
KMail is the email component of Kontact, the integrated personal information manager from KDE. Features. Supports the standard mail protocols IMAP, POP3 ...
And the only thing shown in the browser:
App not found
If we visit the page https://kde.org/applications/internet/ there is an entry for KMail.
The entry refers to https://kde.org/applications/internet/org.kde.kmail2
This seems to be the correct page.
Would it be possible to redirect
Or is this done by intention to differ between kmail and kmail2?
It wants to be kmail2 for some reason, I've added that to exceptions
should deploy in 30 mins or so