Ignore it. Your email is sitting there. That's just a notice for important people in their lives (which wouldn't be us.)
On an interesting note, when I sent my partial to Jessica Regel last night, the same night she sent her response to me, I got one of those.
Patrick's right. All the agents are on vacation. But some of them are checking and answering their email anyway.
If it makes you feel any better there are big thunderstorms on the way on the East Coast, so maybe the agents will be stuck inside reading through their queries.