I was trying to message another iPhone user , he has AT&T and I have Verizon over the weekend . He was not receiving any of my messages or at least very intermittently . And I was not receiving his . As a test, I tried messaging using my sons phone same 4s, Verizon as mine - and it worked . I immediately tried my phone and friend did not get anything . Also we could not get through to each other when trying to call. Three days later and still having issues any.suggestions please !!