Hopefully anyone with an account on my site, got an email

Yes, I did... I also just logged in and chose not to recieve email notices lol...
mail server doesn't know it's supposed to send mail to people not local. Or more to the point, HOW to do so.
I was saying that recipients could be unknowingly having their email filtered; with how anal retentive spam mail filters are becoming it's almost a given that legit email langs in bulk mail bins. Additionally a lot of "missconfigured"/"hijacked" mailservers (or scripts) are exploited daily, which can also land a site in an email blacklist, which also attributes to mail being filtered (even to the circular recycling bin).