Public folder not receiving mail from internal contact

Hi,

I am doing a lab with Exchange 2013 and public folders. I create 1 PF by the book, mail enabled it, gave anonymous users contributor role. Problem is when I send a mail from my test user to a PF, PF stays empty. The user that I am sending mail from is the Owner of the PF. Mail address of the PF is SMTP.

This option to reject messages from all senders is there from the start, is that wrong?

Edit: not receiving NDR as well.

Thanks