I don't understand people complaining with lots of unread emails.. If you didn't read an email from X days ago or older, you won't ever do it. Just mark as read

I don't understand people complaining with lots of unread emails.. If you didn't read an email from X days ago or older, you won't ever do it. Just mark as read all [unread] mail from X days ago till the beginning of Time, and you are set to go.