Spoofing means that you are setting the From address to look like it is coming from a user@domain that is not valid for your mail server.   So if my domain is gizmola.test  and I set up my from to be someuser@yahoo.com, this is "spoofing".  I would need the mail to come from someuser@gizmola.test. You should open up your received email that is in the spam folder for your tests, and look at the actual email headers to see what is in there.  If you want to provide the headers, we might b