How to stop iPhone users from unintentionally sending texts to my email address
Open the messages app on your Mac.
Open preferences from the Messages menu at the top of the screen.
Select the Accounts tab of the preferences window.
Uncheck enable this account


In future iPhone users should not find that messaging you defaults to an iMessages and rather to a SMS message.

The following video demonstrates these steps:

https://youtu.be/C5ilqv8NruE

This is a particularly nasty ongoing bug which does not rely on ever having had a iPhone and is particularly difficult to detect because the sender thinks they have sent you a text message(s) and the (non-)receiver is none-the-wiser that they are missing any messages/ignoring someone.