Here’s the quandry.
All parties in this question have Verizon as a carrier. Some are iPhones and some are android.
I have an iPhone 4s and can text my friend who has an iPhone 4. He get’s my text and he can text me and I get the msg.
His wife has an android and can text him and he can text her. They both get msgs.
Another friend has an android but sends him a text and he can’t get it and vice-versa.
Another friend has an iPhone and texts him and he can’t get it and vice versa.