My housemate has a business website that receives and sends email enquiries. When his phone or his laptop are connected to the TPG NBN home wifi he can neither send nor receive any new emails to this account. He does not have this issue when he is hotspotted to his Optus phone, but the connection isn't good so he would prefer to be on the wifi. He is not running a VPN. Just a straight connection through the wifi, logging in with the regular password and settings. Can someone please provide some thoughts on how to troubleshoot this?