Not sure if anyone has already mentioned this but just as a reminder, you can only receive 20 RSVP's a day. Same goes with any other requests from neighbors.
Although in the first day I received 22 RSVPs, 2 more than normal for some reason. And then because the game ticked over to a new day, which for me happened to be in that same day, I was able to send out requests to everyone again. Thus in actuality I received 44 RSVP's in the first day. The second day, being the Sunday, responses were slow and much less. But by day 4 I had all RSVPs.
I've also been getting new nbr requests all week which is cool. New nbr's are always welcome!
But getting back to requests, even if you only have 20 active nbr's then within 4 days you should have all RSVP's.
Any new players struggling with nbr's and getting rsvps please feel free to add me. I play daily.