Possible bug?

Hi! Even though we have “Allow Free Emails” turned off, we noticed that the following email format will still be allowed through -> TESTIN10@GMAIL.COM , EREZMA10@GMAIL.COM , TESTIN10@HOTMAIL.COM etc. It is working great, but we noticed that it will still allow all of these through. Is someone able to take a look at this? Appreciate it! 🙂