I was checking my mailbox a few minutes ago, and decided to mark as read about 80 emails in a particular label. I could of course have used "select all" + "select the xxxx messges", mark as read. But I wanted to briefly review them, so it wasn't really an option.
It is actually quite simple:
- Run the search query you want. In my case, it was "label:Foobar" (clicking on the label is enough).
- Add is:unread to your search
- use *u (if you have enabled keyboard shortcuts (you should!)) to select all unread messages
- use shift + i to mark them as read
- the search will be refreshed automatically, instantly excluding the messages you've just mark as read
- repeat until you're done
4 keystrokes per page, quite efficient, you don't even have to touch your mouse :-)