A tiny solution to the email problem: Notification headers

This is something I was thinking about some time ago... Some of my emails aren't really emails, but system messages. Stuff like "Import failed or succeeded" or a password change request email. Also, most of those emails are only valuable during a brief period of time (The log email of an importer isn't something you need to keep etc). What if there would be a mail header that specifies that an email is a notification email? We could do things like show a popup only on notification emails, automatically delete them if they're read or when expire.

Just curious if there already is such a header and what you think about it.