I was trying to message someone tonight & he wasn’t getting my texts.
Turns out he used to have an iphone but has now moved to a Samsung phone (one of those dark side Android devices).
And if you move off Apple you have to deregister your phone number from iMessage from the Apple servers else your iPhone thinks the number is still on iMessage & tries to deliver via iMessage & of course they aren’t & they won’t get your message.
So my friend…deregistered & presto…instantly I can send him messages (texts) again.
Link of the Apple page to de-register is https://selfsolve.apple.com/deregister-imessage/
There is a form to fill out on that apple website page….see screenshots below.
And I thought I knew most things Apple…but seems I am just a rookie 1