I heard from two contacts yesterday (both on different devices and with different networks) that they had sent me texts, but they did not go through. One got a "text failed" message and the other received an error message saying "no number". When both tried to call me, it went through, so I know that they had services and they have my number correct, especially since I have gotten texts from them in the past. Throughout the day, though, I was getting texts and sending to others without a problem.
I thought the problem was that my phone needed to be updated, so I did that last night and hoped the problem was solved, but today, another contact said she has tried texting with not luck- she has Verizon, but not an iPhone.