Invites lost in the mail?

We sent our wedding invites out last week, and most of our family across the country has gotten theirs. We have heard from one family member that they have yet to receive their invite yet, even though the other family in their area got theirs days prior. We’ve also heard from a local friend that they hadn’t received theirs either! This made my FH and I worried, because we’re not sure if other people haven’t received theirs as well. Our invite links guests to our wedding invite for details and RSVP, and since I’m using Squarespace, I can see IP addresses of who has visited the website, and what city they are in. So far we don’t have as many site visitors as we would have thought, so we’re starting to think that there may be more missing invites than just those two...

So here’s my question. We’re a casual crowd, and we were thinking we could wait a couple weeks (our RSVP deadline is in 3 weeks), and send out a text to some friends we haven’t heard from yet saying something like “We’ve gotten word that some guests never got their invite in the mail, so we’re just checking in to make sure you got yours!” Would you be put off if you got a text like this? Would you just wait until the RSVP deadline and then start hunting people down? We just don’t want to hurt any feelings by people thinking they weren’t invited, when really their invites just got lost in the mail.