A simple scheduled task to run a simple PoSh script would be easiest IMO.

yum-cron and dnf-automatic do not use postfix or any other MTA. They simply open and send with a direct SMTP connection by default.

@scottalanmiller said:

There does not seem to be any trend with this issue. Just one user, in a quick search, reporting the issue. And there was no answer in that case.

FWIW, I've found some additional instances of this issue by searching Google with "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\PushNotifications\AppDB"