My iPhone is reading an android text as iMessage

Hello!

So my husband has never had an iPhone and he used to always send me a regular text message but due to the lovely glitch of my iPhone being unable to push my Gmail email to my iPhone, he set up a script to send a delayed (to whatever time is appropriate) email to my phone via my Verizon ID.

After the first message I received (which was an iMessage), I have not been able to send him an actual text (SMS) message back as a reply. He doesn’t get them as a text, but does receive them as an email. My “send as SMS when iMessage is unavailable” is turned on, and he has tried to reply to our text chat via his regular SMS text in his text message app and doing such has not changed the fact that I still receive his messages as an iMessage.

Does anyone have any suggestions?

Thanks so much for your time!