Text message from iPhone to android phone
 

My neighbor has an iPhone and I have a Samsung (android). In the past we have been able to send text messages to each other's phone. Recently my neighbor got a new iPhone and I bought an iPad. Now any text message from my neighbor appears on my iPad as a message instead of going to my phone. A text message from my Samsung still goes to the iPhone (as usual).
I checked my profile in the iPad and my phone number isn't listed but my email address is. I turned off the message function in the iPad thinking that would force any message to my phone but that didn't work. The text message became undelivered. I'm guessing the problem is with the settings in the iPhone but I know nothing about iPhones. Any suggestions?

Is he sending a message from his iPad to your email address or to your phone number? (it sounds like he is using your email address for some reason)

On your iPhone, go to Setting -> Messages -> Send & Receive (immediately under IMessage). Do your phone number and email address both appear and are they both selected to receive messages?