We received two invitations back but it was after our RSVP deadline. Both of these people are very close to us, (one of them was for the best man) and have already RSVPed so we never realized they never actually got the invitation since we had the option to RSVP through our wedding website. Is it necessary to send the invitations back or is there no point now?
Since it's after the deadline, your venue probably needs a final head count very soon. I would forget the paper invites and just send them the link where they can RSVP online. Since you're close with them, I'm sure they'll understand and respond promptly.
I think it would be worth contacting them, saying the mail got returned, sharing a pic of the invite, and asking if they want you to resend the paper invite. Most people wouldn’t want it but some might want one to save! I think it is at least worth addressing with them bc personally I would start feeling a little weird if I didn’t get a physical invite