Importing old text to new text app
I'm currently using a Huawei Mate 9 with AT&T. I am unable to send group messages to more than 10 people for some reason. I have searched online and read that this is an ATT limitation but my wife and kids can send to 10+ with their iPhones. I'm not sure if this is an issue with my phone or with the stock Google messenger app. I guess my question is can I download another app that will allow me to do this and import my old messages and where the sender's won't have to install the same app?