My friend and I realized that we are no longer able to text each other, on each of our phones the texts show they went through, no error messages, but the other person never receives it. This has been going on for months. Just today we each sent texts to each other while we were sitting together and neither one of them went through even though they show that they did. We both have AT&T. I have an iPhone 3Gs, not sure what type of phone hers is. Any idea what could be causing this? We have no issues sending/receiving texts from other people.